 {"id":4557,"date":"2017-08-22T03:59:54","date_gmt":"2017-08-22T01:59:54","guid":{"rendered":"http:\/\/gap47.astrosurf.com\/?page_id=4557"},"modified":"2019-12-19T18:50:23","modified_gmt":"2019-12-19T16:50:23","slug":"realisation-miroir-400","status":"publish","type":"page","link":"https:\/\/gap47.astrosurf.com\/index.php\/technique\/optique-instruments\/construction-du-dobson-t-400\/realisation-miroir-400\/","title":{"rendered":"R\u00e9alisation de l&rsquo;optique"},"content":{"rendered":"<p><span style=\"font-size: 24px;\"><strong><span style=\"font-family: arial, helvetica, sans-serif;\"><span style=\"font-size: 20px;\">La r\u00e9alisation de l&rsquo;optique sera divis\u00e9e en plusieurs parties :<\/span> <\/span><\/strong><\/span><\/p>\n<p><span style=\"color: #008000; font-family: times\\ new\\ roman, times, serif; font-size: 20px;\"><em>Vous pouvez aller directement \u00e0 la section qui vous int\u00e9resse en cliquant sur l&rsquo;un des choix ci-dessous. Vous pourrez ensuite revenir directement ici avec la fl\u00e8che retour de votre navigateur.<\/em><\/span><\/p>\n<p><strong><span style=\"font-size: 20px; font-family: times\\ new\\ roman, times, serif;\">1 &#8211; <a href=\"#o1\">Pr\u00e9paratifs<\/a><\/span><\/strong><br \/>\n<span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\"> 2 &#8211; <a href=\"#o2\">R\u00e9unissage<\/a><\/span><\/strong><\/span><br \/>\n<span style=\"font-size: 20px;\"> <strong><span style=\"font-family: times\\ new\\ roman, times, serif;\"> 3 &#8211; <a href=\"#o3\">Doucissage<\/a><\/span><\/strong><\/span><br \/>\n<span style=\"font-size: 20px;\"> <strong><span style=\"font-family: times\\ new\\ roman, times, serif;\"> 4 &#8211; <a href=\"#o4\">Polissage<\/a><\/span><\/strong><\/span><br \/>\n<span style=\"font-size: 20px;\"> <strong><span style=\"font-family: times\\ new\\ roman, times, serif;\"> 5 &#8211; <a href=\"#o5\">Parabolisation<\/a><\/span><\/strong><\/span><br \/>\n<span style=\"font-size: 20px;\"> <strong><span style=\"font-family: times\\ new\\ roman, times, serif;\"> 6 &#8211; <a href=\"#o6\">Contr\u00f4les<\/a><\/span><\/strong><\/span><\/p>\n<p><em><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px; color: #008000;\">Dans cette page, certaines photos et\/ou illustrations sont \u00ab\u00a0cliquables\u00a0\u00bb, c&rsquo;est \u00e0 dire qu&rsquo;en cliquant sur elles cela fera appara\u00eetre la photo en plus grande taille. Pour distinguer celles qui sont cliquables de celles qui ne le sont pas, quand vous survolez une image, un dessin ou une vid\u00e9o avec votre curseur (g\u00e9n\u00e9ralement en forme de fl\u00e8che) celui-ci prend alors la forme d&rsquo;une main. Pour revenir \u00e0 la page, cliquez sur la croix en haut \u00e0 droite ou tapez sur la touche ESCAPE de votre clavier.<br \/>\n<\/span><\/em><\/p>\n<hr>\n<p>&#8211;<a id=\"o1\"><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 24px;\"><strong>Pr\u00e9paratifs<\/strong><\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\"><strong>&nbsp;<\/strong><\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Dans un souci d\u2019\u00e9quit\u00e9, nous avons d\u00e9cid\u00e9 de partager nos commandes entre les deux artisans opticiens fran\u00e7ais au service des amateurs \u00e0 l&rsquo;\u00e9poque&nbsp;:<\/span><\/p>\n<ul>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La soci\u00e9t\u00e9 <a href=\"http:\/\/www.mirro-sphere.com\/\" target=\"_blank\" rel=\"noopener noreferrer\">Mirro Sph\u00e8re<\/a> (Franck Gri\u00e8re) sera sollicit\u00e9e pour la fourniture du blank.<\/span><\/li>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La soci\u00e9t\u00e9 Astrot\u00e9lescope (Jean-Marc Lecleire) nous procurera quant \u00e0 elle le kit d&rsquo;abrasifs et de produits \u00e0 polir.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Nous avons donc pass\u00e9 commande le 25 ao\u00fbt 2007 d&rsquo;un disque de Suprax de 410 mm de diam\u00e8tre et 45 mm d&rsquo;\u00e9paisseur. Nous avons opt\u00e9 pour un disque pr\u00e9-\u00e9bauch\u00e9. En effet, cette phase du travail ne pr\u00e9sentait pas \u00e0 nos yeux un grand int\u00e9r\u00eat et l&rsquo;\u00e9conomie par rapport au co\u00fbt de quelques kilos de carbo n\u00e9cessaires au dressage des faces et \u00e0 la r\u00e9alisation de la courbure \u00e9tait relativement minime.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le disque brut de Suprax a \u00e9t\u00e9 d\u00e9coup\u00e9 dans un blank de 600 mm de diam\u00e8tre par un sous-traitant de Mirro Sph\u00e8re. La technique utilis\u00e9e est celle de la d\u00e9coupe au jet d&rsquo;eau abrasif sous pression. Le disque a ensuite \u00e9t\u00e9 pr\u00e9-\u00e9bauch\u00e9 et d\u00e9bord\u00e9 \u00e0 la meule diamant\u00e9e par Franck Gri\u00e8re. Un r\u00e9unissage de la surface concave et du dos a enfin \u00e9t\u00e9 r\u00e9alis\u00e9 par ses soins.<\/span><\/p>\n<p><a href=\"https:\/\/youtu.be\/zfrxfSGqmHg?t=4\" target=\"_blank\" rel=\"noopener noreferrer\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6981\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1247.jpg\" alt=\"\" width=\"2592\" height=\"1944\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1247.jpg 2592w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1247-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1247-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1247-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-6642 aligncenter\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/CONVAR3.jpg\" alt=\"\" width=\"1000\" height=\"666\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/CONVAR3.jpg 800w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/CONVAR3-300x200.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/CONVAR3-768x512.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><em><span style=\"font-family: times\\ new\\ roman, times, serif;\"><span style=\"font-size: 20px;\">Miroir de 400 mm pr\u00e9-\u00e9bauch\u00e9<\/span><br \/>\n<\/span><\/em><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Nous avons r\u00e9cup\u00e9r\u00e9 le blank pr\u00e9-\u00e9bauch\u00e9 le 11 octobre 2007 dans l&rsquo;atelier de Mirro Sph\u00e8re \u00e0 Marzy.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le kit d&rsquo;abrasifs et produits \u00e0 polir command\u00e9 chez Astrot\u00e9lescope comprenait&nbsp;:<\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-02-a\u0300-00.16.13.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6644 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-02-a\u0300-00.16.13.png\" alt=\"\" width=\"1378\" height=\"460\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-02-a\u0300-00.16.13.png 1378w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-02-a\u0300-00.16.13-300x100.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-02-a\u0300-00.16.13-768x256.png 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<table style=\"width: 598px; height: 260px;\">\n<tbody>\n<tr style=\"height: 10px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 10px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>N\u00b0<\/strong><\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 10px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Produit<\/strong><\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 10px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Nature<\/strong><\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 10px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Poids<\/strong><\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 10px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Phase concern\u00e9e<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">C120<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Carborundum<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1 kg<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">R\u00e9unissage<\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">5<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">W180<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Grenat<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">500 g<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Fin R\u00e9unissage, Doucissage<\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">W240<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Grenat<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">500 g<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Doucissage<\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">C400<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Carborundum<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">250 g<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Doucissage<\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">4<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">W6<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Grenat<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">200 g<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Doucissage<\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">C1200<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Carborundum<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">200 g<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Fin Doucissage<\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">7<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">C\u00e9rite 415<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Oxyde de C\u00e9rium<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">500 g<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Polissage<\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">8<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Oxycon<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Oxyde de Zirconium<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">250 g<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Fin Polissage, Parabolisation<\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">9<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Opaline<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Oxyde de C\u00e9rium raffin\u00e9<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">150 g<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Fin Parabolisation<\/span><\/td>\n<\/tr>\n<tr style=\"height: 25px;\">\n<td style=\"width: 19.6094px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">10<\/span><\/td>\n<td style=\"width: 68.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Poix<\/span><\/td>\n<td style=\"width: 169.219px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Gugolz 55 n\u00b0 10<\/span><\/td>\n<td style=\"width: 57.2188px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3 kg<\/span><\/td>\n<td style=\"width: 226.609px; text-align: center; height: 25px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Polissage, Parabolisation<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La grande quantit\u00e9 de poix command\u00e9e s&rsquo;explique par le nombre de polissoirs n\u00e9cessaires au polissage et \u00e0 la parabolisation (pleine taille et subdiam\u00e9traux).<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Par pr\u00e9caution, nous avons v\u00e9rifi\u00e9 que le disque ne pr\u00e9sentait pas des tensions internes. Pour cela, nous avons utilis\u00e9 un filtre polarisant retir\u00e9 d\u00e9licatement d&rsquo;un \u00e9cran LCD de t\u00e9l\u00e9viseur.<\/span><\/p>\n<table style=\"width: 779.3px;\">\n<tbody>\n<tr style=\"height: 181.667px;\">\n<td style=\"width: 379.75px; height: 181.667px; text-align: center; vertical-align: bottom;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0066.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6656\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0066.jpg\" alt=\"\" width=\"386\" height=\"290\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0066.jpg 2048w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0066-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0066-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0066-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 386px) 100vw, 386px\" \/><\/a><\/td>\n<td style=\"width: 383.75px; height: 181.667px; text-align: center; vertical-align: bottom;\">&nbsp;<a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Contraintes.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6658\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Contraintes.jpg\" alt=\"\" width=\"700\" height=\"525\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Contraintes.jpg 2048w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Contraintes-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Contraintes-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Contraintes-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" \/><\/a><\/td>\n<\/tr>\n<tr style=\"height: 26px;\">\n<td style=\"width: 379.75px; text-align: center; height: 26px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><em>Mat\u00e9riel utilis\u00e9 pour le contr\u00f4le des tensions<\/em><\/span><\/td>\n<td style=\"width: 383.75px; text-align: center; height: 26px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><em>Contr\u00f4le des tensions<br \/>\n<\/em><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><em>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br \/>\n<\/em><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Comme on peut le constater dans la vid\u00e9o ci-dessus \u00e0 droite, aucun d\u00e9grad\u00e9 de teinte n\u2019appara\u00eet lors de l&rsquo;extinction par rotation du filtre polarisant. Cet \u00e9tat de fait n&rsquo;a rien d&rsquo;\u00e9tonnant car des d\u00e9fauts de tensions significatifs n&rsquo;ont jamais \u00e9t\u00e9 rapport\u00e9s sur ce type de verre (Borosilicate moul\u00e9).<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Pour le travail aux abrasifs, nous avons opt\u00e9 pour un outil segment\u00e9 \u00e0 base de carreaux de gr\u00e8s c\u00e9rame sur support bois. Ce disque est constitu\u00e9 de plusieurs \u00e9paisseurs&nbsp; de contreplaqu\u00e9. Il recevra trois couches de vernis de marine afin de le rendre parfaitement \u00e9tanche \u00e0 l&rsquo;eau. Les carreaux de gr\u00e8s c\u00e9rame seront fix\u00e9s au disque via une fine couche de poix. Nous avons pr\u00e9f\u00e9r\u00e9 cette option \u00e0 un collage afin de b\u00e9n\u00e9ficier des qualit\u00e9s de souplesse de la poix. En effet, il nous sera ainsi possible de presser l&rsquo;ensemble des carreaux sur le miroir entre deux s\u00e9ances de travail afin de garantir le maintien durable de la forme de l&rsquo;outil ce qui semble \u00e0 priori plus al\u00e9atoire avec un collage classique.<\/span><\/p>\n<table>\n<tbody>\n<tr>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6662\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Acr76474284567187214151.jpg\" alt=\"\" width=\"946\" height=\"700\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Acr76474284567187214151.jpg 946w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Acr76474284567187214151-300x222.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Acr76474284567187214151-768x568.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<td><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6663 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/collage05.jpg\" alt=\"\" width=\"1150\" height=\"636\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/collage05.jpg 1150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/collage05-300x166.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/collage05-768x425.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/collage05-450x250.jpg 450w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><em>D\u00e9tail de la fabrication de l&rsquo;outil segment\u00e9<\/em><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr>\n<p>&#8211;<a id=\"o2\"><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 24px;\"><strong><span style=\"font-family: arial, helvetica, sans-serif;\">R\u00e9unissage<\/span><\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La surface concave pr\u00e9-\u00e9bauch\u00e9e \u00e0 la meule diamant\u00e9e est relativement brute. Il convient donc de l&rsquo;homog\u00e9n\u00e9iser et tendre vers une forme sph\u00e9rique la plus parfaite possible tout en ajustant le rayon de courbure \u00e0 la valeur cible souhait\u00e9e&nbsp;: Ce sont les objectifs du r\u00e9unissage.<\/span><\/p>\n<table style=\"width: 644.65px;\">\n<tbody>\n<tr>\n<td style=\"width: 316px;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6665 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/100_3314_1.jpg\" alt=\"\" width=\"1024\" height=\"682\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/100_3314_1.jpg 1024w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/100_3314_1-300x200.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/100_3314_1-768x512.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<td style=\"width: 311.65px;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6666\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/100_3340.jpg\" alt=\"\" width=\"1024\" height=\"682\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/100_3340.jpg 800w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/100_3340-300x200.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/100_3340-768x512.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-size: 20px; font-family: times\\ new\\ roman, times, serif;\">L&rsquo;abrasif utilis\u00e9 \u00e0 ce stade \u00e9tait le Carbo 120 avec des courses normales en W ou en Y. Afin d&rsquo;augmenter le rendement du travail, des masselottes de 2,5 kg chacune ont \u00e9t\u00e9 dispos\u00e9es sur le disque sup\u00e9rieur.<\/span><\/p>\n<p><span style=\"font-size: 20px; font-family: times\\ new\\ roman, times, serif;\">L&rsquo;homog\u00e9n\u00e9it\u00e9 de la forme sph\u00e9rique a \u00e9t\u00e9 contr\u00f4l\u00e9e par la m\u00e9thode du quadrillage de la surface du miroir au feutre ind\u00e9l\u00e9bile.<\/span><\/p>\n<table style=\"width: 653px;\">\n<tbody>\n<tr>\n<td style=\"width: 319.483px;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1254_1.jpg\" alt=\"\" width=\"1024\" height=\"768\"><\/td>\n<td style=\"width: 315.517px;\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-6668 aligncenter\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1255_1.jpg\" alt=\"\" width=\"1024\" height=\"768\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1255_1.jpg 1024w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1255_1-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1255_1-768x576.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L&rsquo;ajustement du rayon de courbure a \u00e9t\u00e9 r\u00e9alis\u00e9 au sph\u00e9rom\u00e8tre \u00e9quip\u00e9 d&rsquo;un comparateur. La position du miroir a \u00e9t\u00e9 altern\u00e9e dessus\/dessous afin d&rsquo;homog\u00e9n\u00e9iser la sph\u00e8re mais \u00e9galement pour ajuster le rayon de courbure. Dans le cas pr\u00e9sent, les s\u00e9ch\u00e9es miroir dessus ont \u00e9t\u00e9 plus nombreuses car le rayon de courbure devait \u00eatre un peu raccourci.<\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1082_1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6670\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1082_1.jpg\" alt=\"\" width=\"1500\" height=\"1125\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1082_1.jpg 1024w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1082_1-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1082_1-768x576.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<table style=\"width: 656.733px;\">\n<tbody>\n<tr style=\"height: 30px;\">\n<td style=\"width: 133px; text-align: center; height: 60px;\" rowspan=\"2\">&nbsp;<\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Date<\/strong><\/span><\/td>\n<td style=\"width: 268px; height: 30px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Nombre de s\u00e9ch\u00e9es<\/strong><\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 60px;\" rowspan=\"2\">&nbsp;<\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Total des s\u00e9ch\u00e9es<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 30px;\">\n<td style=\"width: 133px; height: 30px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Miroir dessus<\/strong><\/span><\/td>\n<td style=\"width: 135px; height: 30px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Miroir dessous<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 10.2168px;\">\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">24\/11\/2007<\/span><\/td>\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<td style=\"width: 135px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">30\/11\/2007<\/span><\/td>\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">12<\/span><\/td>\n<td style=\"width: 135px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">15<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">07\/12\/2007<\/span><\/td>\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">14<\/span><\/td>\n<td style=\"width: 135px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1<\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">15<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">08\/12\/2007<\/span><\/td>\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">14<\/span><\/td>\n<td style=\"width: 135px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">0<\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">14<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">14\/12\/2007<\/span><\/td>\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">11<\/span><\/td>\n<td style=\"width: 135px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">0<\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">11<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">22\/12\/2007<\/span><\/td>\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">10<\/span><\/td>\n<td style=\"width: 135px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">0<\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">10<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">04\/01\/2008<\/span><\/td>\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">8<\/span><\/td>\n<td style=\"width: 135px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">4<\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">12<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">11\/01\/2008<\/span><\/td>\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<td style=\"width: 135px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1<\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">4<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>TOTAL<\/strong><\/span><\/td>\n<td style=\"width: 133px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>75<\/strong><\/span><\/td>\n<td style=\"width: 135px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>12<\/strong><\/span><\/td>\n<td style=\"width: 210.733px; text-align: center; height: 20px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>87<\/strong><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr>\n<p>&#8211;<a id=\"o3\"><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: arial, helvetica, sans-serif; font-size: 24px;\"><strong>Doucissage<\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La phase de doucissage ne pr\u00e9sente pas de difficult\u00e9 particuli\u00e8re. On s&rsquo;attachera \u00e0 v\u00e9rifier&nbsp; l\u2019\u00e9limination des piq\u00fbres du grain pr\u00e9c\u00e9dent et \u00e0 maintenir le rayon de courbure \u00e0 la valeur pr\u00e9alablement d\u00e9finie. La principale pr\u00e9occupation se limitera \u00e0 pr\u00e9venir toute contamination d&rsquo;un grain issu d&rsquo;une session pr\u00e9c\u00e9dente qui pourrait causer des rayures et un retour en arri\u00e8re dans la phase de doucissage. Un soin extr\u00eame a donc \u00e9t\u00e9 apport\u00e9 au nettoyage.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les m\u00eames types de courses normales que pour le r\u00e9unissage ont \u00e9t\u00e9 utilis\u00e9es en variant les amplitudes, les formes et en alternant les op\u00e9rateurs. Le poids rajout\u00e9 \u00e0 \u00e9t\u00e9 progressivement diminu\u00e9 jusqu&rsquo;\u00e0 \u00eatre \u00e9limin\u00e9 \u00e0 la fin du doucissage.<\/span><\/p>\n<table style=\"width: 712px;\">\n<tbody>\n<tr>\n<td style=\"width: 343.983px;\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-6673 aligncenter\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/2008-03-14_T400_0895_1.jpg\" alt=\"\" width=\"1024\" height=\"768\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/2008-03-14_T400_0895_1.jpg 1024w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/2008-03-14_T400_0895_1-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/2008-03-14_T400_0895_1-768x576.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/strong><\/td>\n<td style=\"width: 345.017px;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6674\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1000982.jpg\" alt=\"\" width=\"1024\" height=\"768\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1000982.jpg 3264w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1000982-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1000982-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1000982-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L&rsquo;\u00e9volution de la disparition des piq\u00fbres du grain pr\u00e9c\u00e9dent a \u00e9t\u00e9 mesur\u00e9e \u00e0 l&rsquo;aide d&rsquo;un oculaire sur plusieurs zones de la surface avec un \u00e9clairage puissant au dos du miroir.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le chanfrein a quant \u00e0 lui \u00e9t\u00e9 entretenu \u00e0 l&rsquo;avancement avec des pierres abrasives de granulom\u00e9tries comparables \u00e0 celle utilis\u00e9es pour le travail de la surface optique. Pour faciliter cette op\u00e9ration, nous avons install\u00e9 le miroir sur un plateau tournant motoris\u00e9.<\/span><\/p>\n<table style=\"width: 709px;\">\n<tbody>\n<tr>\n<td style=\"width: 345.6px;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6677 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1279_1.jpg\" alt=\"\" width=\"1024\" height=\"768\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1279_1.jpg 1024w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1279_1-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1279_1-768x576.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<td style=\"width: 344.4px;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6678 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_0313_1.jpg\" alt=\"\" width=\"1024\" height=\"768\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_0313_1.jpg 1024w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_0313_1-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_0313_1-768x576.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le tableau de marche du doucissage a \u00e9t\u00e9 le suivant&nbsp;:<\/span><\/p>\n<table class=\" aligncenter\" style=\"width: 750.1px; border-color: #000000;\">\n<tbody>\n<tr style=\"height: 50px; background-color: #c8c8c8;\">\n<td style=\"height: 50px; width: 424.083px; text-align: center;\" colspan=\"5\"><span style=\"font-family: times\\ new\\ roman, times, serif;\"><strong>C180<\/strong><\/span><\/td>\n<td style=\"height: 50px; width: 455.617px; text-align: center;\" colspan=\"5\"><span style=\"font-family: times\\ new\\ roman, times, serif;\"><strong>C240<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 52.2666px;\">\n<td style=\"height: 52.2666px; width: 80px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Dates<\/strong><\/span><\/td>\n<td style=\"height: 52.2666px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Miroir dessus<br \/>\n<\/strong><\/span><\/td>\n<td style=\"height: 52.2666px; width: 324.083px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Miroir dessous<\/strong><\/span><\/td>\n<td style=\"height: 52.2666px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Dates<\/strong><\/span><\/td>\n<td style=\"height: 52.2666px; width: 314.517px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Miroir dessus<\/strong><\/span><\/td>\n<td style=\"height: 52.2666px; width: 121.1px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Miroir dessous<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 80px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">19\/01\/2008<\/span><\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">12<\/span><\/td>\n<td style=\"height: 50px; width: 324.083px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">16\/02\/2008<\/span><\/td>\n<td style=\"height: 50px; width: 314.517px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">10<\/span><\/td>\n<td style=\"height: 50px; width: 121.1px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 80px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">01\/02\/2008<\/span><\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">12<\/span><\/td>\n<td style=\"height: 50px; width: 324.083px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">17\/02\/2008<\/span><\/td>\n<td style=\"height: 50px; width: 314.517px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">9<\/span><\/td>\n<td style=\"height: 50px; width: 121.1px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">4<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 80px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">02\/02\/2008<\/span><\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<td style=\"height: 50px; width: 324.083px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">18\/02\/2008<\/span><\/td>\n<td style=\"height: 50px; width: 314.517px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">8<\/span><\/td>\n<td style=\"height: 50px; width: 121.1px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 80px; text-align: center;\">&nbsp;<\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"height: 50px; width: 324.083px; text-align: center;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">22\/02\/2008<\/span><\/td>\n<td style=\"height: 50px; width: 314.517px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<td style=\"height: 50px; width: 121.1px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 80px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Total<\/span><\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">30<\/span><\/td>\n<td style=\"height: 50px; width: 324.083px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">15<\/span><\/td>\n<td style=\"height: 50px; width: 20px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Total<\/span><\/td>\n<td style=\"height: 50px; width: 314.517px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">33<\/span><\/td>\n<td style=\"height: 50px; width: 121.1px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">12<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 100px; text-align: center;\" colspan=\"3\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>TOTAL<\/strong><\/span><\/td>\n<td style=\"height: 50px; width: 324.083px; text-align: center;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>45<\/strong><\/span><\/td>\n<td style=\"height: 50px; width: 334.517px; text-align: center;\" colspan=\"4\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>TOTAL<\/strong><\/span><\/td>\n<td style=\"height: 50px; width: 121.1px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>45<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 100px; text-align: center;\" colspan=\"3\">&nbsp;<\/td>\n<td style=\"height: 50px; width: 324.083px; text-align: center;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"height: 50px; width: 334.517px; text-align: center;\" colspan=\"4\">&nbsp;<\/td>\n<td style=\"height: 50px; width: 121.1px; text-align: center;\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 50px; background-color: #c8c8c8;\">\n<td style=\"height: 50px; text-align: center; width: 424.083px;\" colspan=\"5\"><span style=\"font-family: times\\ new\\ roman, times, serif;\"><strong>C400<\/strong><\/span><\/td>\n<td style=\"height: 50px; text-align: center; width: 455.617px;\" colspan=\"5\"><span style=\"font-family: times\\ new\\ roman, times, serif;\"><strong>W6<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 77px;\">\n<td style=\"text-align: center; height: 77px; width: 80px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dates<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 77px; width: 20px;\" colspan=\"2\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Miroir dessus<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 77px; width: 324.083px;\" colspan=\"2\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Miroir dessous<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 77px; width: 20px;\" colspan=\"2\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dates<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 77px; width: 314.517px;\" colspan=\"2\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Miroir dessus<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 77px; width: 121.1px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Miroir dessous<\/span><\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"text-align: center; height: 50px; width: 80px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">01\/03\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">12<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">28\/03\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 314.517px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">7<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 121.1px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"text-align: center; height: 50px; width: 80px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">07\/03\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">12<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">5<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">11\/04\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 314.517px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">9<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 121.1px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">4<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"text-align: center; height: 50px; width: 80px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">14\/03\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">12\/04\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 314.517px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">10<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 121.1px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"text-align: center; height: 50px; width: 80px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">15\/03\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">4<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 314.517px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 121.1px;\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"text-align: center; height: 50px; width: 80px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Total<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">36<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">17<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Total<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 314.517px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">26<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 121.1px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">12<\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"text-align: center; height: 50px; width: 100px;\" colspan=\"3\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>TOTAL<\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>53<\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 334.517px;\" colspan=\"4\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>TOTAL<\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 121.1px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>38<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"text-align: center; height: 50px; width: 100px;\" colspan=\"3\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 334.517px;\" colspan=\"4\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 121.1px;\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 50px; background-color: #c8c8c8;\">\n<td style=\"height: 50px; width: 90px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 364.083px;\" colspan=\"6\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>C1200<\/strong><\/span><\/td>\n<td style=\"height: 50px; width: 425.617px;\" colspan=\"2\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 77px;\">\n<td style=\"height: 77px; width: 90px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 77px; width: 20px;\" colspan=\"2\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dates<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 77px; width: 324.083px;\" colspan=\"2\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Miroir dessus<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 77px; width: 20px;\" colspan=\"2\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Miroir dessous<\/span><\/strong><\/span><\/td>\n<td style=\"height: 77px; width: 425.617px;\" colspan=\"2\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 90px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">26\/04\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">8<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<td style=\"height: 50px; width: 425.617px;\" colspan=\"2\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 90px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">02\/05\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">9<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">4<\/span><\/td>\n<td style=\"height: 50px; width: 425.617px;\" colspan=\"2\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 90px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">09\/05\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">6<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1<\/span><\/td>\n<td style=\"height: 50px; width: 425.617px;\" colspan=\"2\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 90px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">10\/05\/2008<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2<\/span><\/td>\n<td style=\"height: 50px; width: 425.617px;\" colspan=\"2\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 90px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Total<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 324.083px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">26<\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">10<\/span><\/td>\n<td style=\"height: 50px; width: 425.617px;\" colspan=\"2\">&nbsp;<\/td>\n<\/tr>\n<tr style=\"height: 50px;\">\n<td style=\"height: 50px; width: 90px;\" colspan=\"2\">&nbsp;<\/td>\n<td style=\"text-align: center; height: 50px; width: 344.083px;\" colspan=\"4\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>TOTAL<\/strong><\/span><\/td>\n<td style=\"text-align: center; height: 50px; width: 20px;\" colspan=\"2\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>36<\/strong><\/span><\/td>\n<td style=\"height: 50px; width: 425.617px;\" colspan=\"2\">&nbsp;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"text-align: center;\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Soit un nombre total de s\u00e9ch\u00e9es qui s&rsquo;\u00e9l\u00e8ve 217 ce qui est largement sup\u00e9rieur \u00e0 celui requis car nous avons pris le parti de prendre de la marge pour plus de s\u00e9curit\u00e9 sur le r\u00e9sultat obtenu.<\/span><\/p>\n<hr>\n<p>&#8211;<a id=\"o4\"><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 24px;\"><strong><span style=\"font-family: arial, helvetica, sans-serif;\">Polissage<\/span><\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Pour le polissage nous allons r\u00e9utiliser la base bois de l&rsquo;outil pleine taille. Une fois d\u00e9barrass\u00e9 de ses carreaux, il sera nettoy\u00e9 et rev\u00eatu de nouvelles couches de vernis. Le polissoir sera fabriqu\u00e9 selon la classique m\u00e9thode Texereau&nbsp;: poix coul\u00e9e en goulottes, carr\u00e9s d\u00e9coup\u00e9s (40 mm x 40mm) et coll\u00e9s \u00e0 chaud sur l&rsquo;outil.<\/span><\/p>\n<table style=\"width: 739px;\">\n<tbody>\n<tr>\n<td style=\"width: 360.45px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030028.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6686\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030028.jpg\" alt=\"\" width=\"1200\" height=\"900\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030028.jpg 3264w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030028-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030028-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030028-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 360.55px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030067.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6687 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030067.jpg\" alt=\"\" width=\"3264\" height=\"2448\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030067.jpg 3264w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030067-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030067-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030067-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Afin d&rsquo;optimiser le pressage, nous utiliserons une lampe \u00e0 infrarouge pour r\u00e9chauffer la poix. Pour le nettoyage du miroir et du polissoir en fin de s\u00e9ance, nous utiliserons un support inclin\u00e9 fabriqu\u00e9 dans une section de tube PVC d&rsquo;assainissement.<\/span><\/p>\n<table style=\"width: 756px;\">\n<tbody>\n<tr>\n<td style=\"width: 403.883px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030225.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6689\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030225.jpg\" alt=\"\" width=\"1200\" height=\"900\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030225.jpg 3264w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030225-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030225-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030225-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 329.117px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060019.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6690\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060019.jpg\" alt=\"\" width=\"990\" height=\"900\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060019.jpg 2076w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060019-300x273.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060019-768x698.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060019-1319x1200.jpg 1319w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le polissage du miroir d\u00e9marre le 30 mai 2008. Il est d\u2019abord r\u00e9alis\u00e9 au polissoir pleine taille \u00e0 la machine pantographe en alternant miroir dessous et miroir dessus&nbsp;:<\/span><\/p>\n<table style=\"width: 755px;\">\n<tbody>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Date<\/span><\/strong><\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dur\u00e9e<\/span><\/strong><\/span><\/td>\n<td style=\"width: 186.417px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Position<\/span><\/strong><\/span><\/td>\n<td style=\"width: 149.583px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Ajout poids<\/span><\/strong><\/span><\/td>\n<td style=\"width: 149px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Temp\u00e9rature<\/span><\/strong><\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">30\/05\/2008<\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3h00<\/span><\/td>\n<td style=\"width: 186.417px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Miroir dessous<\/span><\/td>\n<td style=\"width: 149.583px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">N\u00e9ant<\/span><\/td>\n<td style=\"width: 149px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">20\u00b0C<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">07\/06\/2008<\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3h00<\/span><\/td>\n<td style=\"width: 186.417px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Miroir dessus<\/span><\/td>\n<td style=\"width: 149.583px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">N\u00e9ant<\/span><\/td>\n<td style=\"width: 149px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">19 \u00e0 20\u00b0C<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">En position \u00ab&nbsp;dessus&nbsp;\u00bb, le miroir est entra\u00een\u00e9 gr\u00e2ce \u00e0 3 touches lat\u00e9rales solidaires d\u2019un plateau sup\u00e9rieur (voir ci-dessous).<\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030227.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6940 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030227.jpg\" alt=\"\" width=\"3264\" height=\"2448\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030227.jpg 3264w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030227-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030227-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1030227-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p class=\"Corpsdetexte21\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le miroir est ensuite transf\u00e9r\u00e9 sur la machine double excentrique afin d\u2019en v\u00e9rifier l\u2019efficacit\u00e9. <\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/index.php\/les-machines-du-gap47\/\" target=\"_blank\" rel=\"noopener noreferrer\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Pour plus de pr\u00e9cisions sur le fonctionnement des machines du GAP47 (pantographe, machine \u00e0 double excentrique,&#8230;), reportez-vous \u00e0 cette page.<\/span><\/a><\/p>\n<p class=\"Corpsdetexte21\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le travail est r\u00e9alis\u00e9 en pleine taille, miroir dessous. Le d\u00e9roul\u00e9 des sessions est le suivant&nbsp;:<\/span><\/p>\n<table style=\"width: 693px;\">\n<tbody>\n<tr>\n<td style=\"width: 93px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Date<\/span><\/strong><\/span><\/td>\n<td style=\"width: 76px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dur\u00e9e<\/span><\/strong><\/span><\/td>\n<td style=\"width: 91.85px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">D\u00e9bord<\/span><\/strong><\/span><\/td>\n<td style=\"width: 114.15px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Ajout poids<\/span><\/strong><\/span><\/td>\n<td style=\"width: 95px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Vitesse bras<\/span><\/strong><\/span><\/td>\n<td style=\"width: 144px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Temp\u00e9rature<\/span><\/strong><\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 93px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">13\/06\/2008<\/span><\/td>\n<td style=\"width: 76px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2h30<\/span><\/td>\n<td style=\"width: 91.85px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">25%<\/span><\/td>\n<td style=\"width: 114.15px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">N\u00e9ant<\/span><\/td>\n<td style=\"width: 95px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">8t \/ mn<\/span><\/td>\n<td style=\"width: 144px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">20 \u00e0 21\u00b0C<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 93px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">27\/06\/2008<\/span><\/td>\n<td style=\"width: 76px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1h00<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1h00<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1h00<\/span><\/td>\n<td style=\"width: 91.85px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1\/3D \u00e0 \u00bc D<\/span><\/td>\n<td style=\"width: 114.15px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2 kg<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1 kg<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">N\u00e9ant<\/span><\/td>\n<td style=\"width: 95px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">25t \/ mn<\/span><\/td>\n<td style=\"width: 144px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">22\u00b0C<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"Corpsdetexte21\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Un premier contr\u00f4le global du miroir est r\u00e9alis\u00e9 \u00e0 l\u2019appareil de Foucault (couteau et trame de Ronchi)&nbsp;:<\/span><\/p>\n<table style=\"width: 761px;\">\n<tbody>\n<tr>\n<td style=\"width: 337.917px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_080705.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6755 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_080705.jpg\" alt=\"\" width=\"1787\" height=\"1608\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_080705.jpg 1787w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_080705-300x270.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_080705-768x691.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_080705-1334x1200.jpg 1334w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 405.083px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1796.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6756 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1796.jpg\" alt=\"\" width=\"1024\" height=\"768\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1796.jpg 1024w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1796-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1796-768x576.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"Corpsdetexte21\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Celui-ci r\u00e9v\u00e8le des d\u00e9fauts zonaux d\u2019amplitudes relativement mod\u00e9r\u00e9es&nbsp;: au bord (avant-derni\u00e8re zone relev\u00e9e puis derni\u00e8re zone rabattue) et au centre (l\u00e9g\u00e8re bosse). Cette forme g\u00e9n\u00e9rale n\u2019est pas inqui\u00e9tante \u00e0 ce stade. <\/span><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Par contre, un contr\u00f4le sommaire \u00e0 l\u2019\u00e9toile artificielle met en \u00e9vidence un astigmatisme d\u2019ensemble (ovalisation des plages intra et extra). L\u2019\u00e9volution de ce d\u00e9faut sera particuli\u00e8rement \u00e0 surveiller par la suite.<\/span><\/p>\n<p class=\"Corpsdetexte21\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L\u2019activit\u00e9 du travail optique n\u2019\u00e9tant pas compatible avec l\u2019accueil du public \u00e0 l\u2019observatoire en p\u00e9riode estivale, les travaux de polissage sont suspendus pendant les mois de juillet, ao\u00fbt et septembre.<\/span><\/p>\n<p class=\"Corpsdetexte21\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La reprise du travail le 3 octobre 2008 s\u2019effectue \u00e0 la main en pleine taille miroir dessus pendant 30 mn. <\/span><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le miroir est ensuite plac\u00e9 sur la machine double excentrique pendant 2h00 miroir dessous. <\/span><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le 17 octobre, une session de 2h00 est r\u00e9alis\u00e9e \u00e0 la machine pantographe miroir dessous avec le pleine taille. A l\u2019issue de celle-ci, un nouveau contr\u00f4le de l\u2019astigmatisme est r\u00e9alis\u00e9 \u00e0 l\u2019\u00e9toile artificielle&nbsp;:<\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081017.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6757\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081017.jpg\" alt=\"\" width=\"3000\" height=\"479\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081017.jpg 2555w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081017-300x48.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081017-768x123.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081017-2000x319.jpg 2000w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Celui-ci r\u00e9v\u00e8le la persistance de l\u2019astigmatisme (ovalisation des plages intra \/ extra avec rotation de la figure de 90\u00b0).<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les causes de ce d\u00e9faut sont recherch\u00e9es&nbsp;:<\/span><\/p>\n<ul>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Inadaptation du maintien du miroir en position dessus sur la machine pantographe&nbsp;?<\/span><\/li>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Poids rajout\u00e9s dispos\u00e9s directement sur le polissoir et mal r\u00e9partis&nbsp;?<\/span><\/li>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Molleton&nbsp;: Tapis de sol mince sous le miroir trop rigide (couche unique)&nbsp;?<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Afin de pr\u00e9venir et traiter cet astigmatisme, il est d\u00e9cid\u00e9 de&nbsp;:<\/span><\/p>\n<ul>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Rajouter un film \u00e0 bulle en plus du molleton existant<\/span><\/li>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Positionner les poids rajout\u00e9s sur l\u2019axe du doigt d\u2019entra\u00eenement et non sur le disque polissoir<\/span><\/li>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Augmenter le poids rajout\u00e9 pour am\u00e9liorer l\u2019efficacit\u00e9 du polissage et acc\u00e9l\u00e9rer ainsi la r\u00e9sorption de l\u2019astigmatisme.<\/span><\/li>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Abandonner le syst\u00e8me de maintien du miroir en position miroir dessus.<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Sur ces bases, le travail est relanc\u00e9 \u00e0 la machine pantographe&nbsp;:<\/span><\/p>\n<table style=\"width: 688px;\">\n<tbody>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Date<\/span><\/strong><\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dur\u00e9e<\/span><\/strong><\/span><\/td>\n<td style=\"width: 133px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Position<\/span><\/strong><\/span><\/td>\n<td style=\"width: 122.067px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Ajout poids<\/span><\/strong><\/span><\/td>\n<td style=\"width: 164.933px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Temp\u00e9rature<\/span><\/strong><\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">24\/10\/2008<\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2h00<\/span><\/td>\n<td style=\"width: 133px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Miroir dessous<\/span><\/td>\n<td style=\"width: 122.067px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3 kg<\/span><\/td>\n<td style=\"width: 164.933px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">19\u00b0C<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"Corpsdetexte21\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">De nouveaux contr\u00f4les au Foucault sont effectu\u00e9s le 31 octobre 2008&nbsp;:<\/span><\/p>\n<table style=\"width: 794px;\">\n<tbody>\n<tr>\n<td style=\"width: 391.95px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_081031.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6758 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_081031.jpg\" alt=\"\" width=\"1494\" height=\"1416\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_081031.jpg 1494w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_081031-300x284.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_081031-768x728.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_081031-1266x1200.jpg 1266w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 385.05px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6759 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi3_081031.jpg\" alt=\"\" width=\"1024\" height=\"984\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi3_081031.jpg 1024w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi3_081031-300x288.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi3_081031-768x738.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"Corpsdetexte21\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Ils r\u00e9v\u00e8lent une l\u00e9g\u00e8re att\u00e9nuation des d\u00e9fauts zonaux notamment au bord. Le travail de polissage est donc poursuivi dans les m\u00eames conditions&nbsp;:<\/span><\/p>\n<table style=\"width: 684px;\">\n<tbody>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Date<\/span><\/strong><\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dur\u00e9e<\/span><\/strong><\/span><\/td>\n<td style=\"width: 152.283px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Position<\/span><\/strong><\/span><\/td>\n<td style=\"width: 139.717px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Ajout poids<\/span><\/strong><\/span><\/td>\n<td style=\"width: 122px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Temp\u00e9rature<\/span><\/strong><\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">08\/11\/2008<\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1h00<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1h00<\/span><\/td>\n<td style=\"width: 152.283px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Miroir dessous<\/span><\/td>\n<td style=\"width: 139.717px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">3 kg<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1 kg<\/span><\/td>\n<td style=\"width: 122px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">19 \u00e0 20\u00b0C<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">A l\u2019issue de cette session, un nouveau contr\u00f4le au Foucault est r\u00e9alis\u00e9&nbsp;:<\/span><\/p>\n<table style=\"width: 758px;\">\n<tbody>\n<tr>\n<td style=\"width: 366.95px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault2_081206.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6760 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault2_081206.jpg\" alt=\"\" width=\"1607\" height=\"1548\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault2_081206.jpg 1607w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault2_081206-300x289.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault2_081206-768x740.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault2_081206-1246x1200.jpg 1246w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 371.05px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi_Extra_081206.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6761 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi_Extra_081206.jpg\" alt=\"\" width=\"1529\" height=\"1452\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi_Extra_081206.jpg 1529w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi_Extra_081206-300x285.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi_Extra_081206-768x729.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Ronchi_Extra_081206-1264x1200.jpg 1264w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les d\u00e9fauts zonaux ont encore r\u00e9gress\u00e9. La forme d\u2019ensemble tend vers une sph\u00e8re quasi-id\u00e9ale pour engager une parabolisation. Par contre, un nouveau probl\u00e8me est apparu&nbsp;: des rayures sont visibles en plusieurs endroits de la surface. Des clich\u00e9s en strioscopie et en contraste de phase permettent de mieux les mettre en \u00e9vidence&nbsp;:<\/span><\/p>\n<table style=\"width: 764px;\">\n<tbody>\n<tr>\n<td style=\"width: 429.833px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Rayures-2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6762 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Rayures-2.jpg\" alt=\"\" width=\"1944\" height=\"1860\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Rayures-2.jpg 1944w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Rayures-2-300x287.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Rayures-2-768x735.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Rayures-2-1254x1200.jpg 1254w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 310.167px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/contrste_phase_081206.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6763 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/contrste_phase_081206.jpg\" alt=\"\" width=\"1040\" height=\"1392\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/contrste_phase_081206.jpg 1040w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/contrste_phase_081206-224x300.jpg 224w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/contrste_phase_081206-768x1028.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/contrste_phase_081206-897x1200.jpg 897w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Un contr\u00f4le de l\u2019\u00e9volution de l\u2019astigmatisme est \u00e9galement r\u00e9alis\u00e9 \u00e0 l\u2019\u00e9toile artificielle&nbsp;:<\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081206.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6764\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081206.jpg\" alt=\"\" width=\"2000\" height=\"268\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081206.jpg 2912w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081206-300x40.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081206-768x103.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/startest_081206-2000x268.jpg 2000w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Celui-ci r\u00e9v\u00e8le des plages bien circulaires t\u00e9moignant de la r\u00e9sorption compl\u00e8te de l\u2019astigmatisme d\u2019ensemble initialement diagnostiqu\u00e9.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">En pr\u00e9sence d\u2019une faible aberration sph\u00e9rique et en l\u2019absence d\u2019astigmatisme, les conditions \u00e9taient r\u00e9unies pour engager la parabolisation. L\u2019apparition de ces rayures pourrait malheureusement compromettre ce sc\u00e9nario.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Il est donc d\u00e9cid\u00e9 de r\u00e9aliser quelques heures suppl\u00e9mentaires de polissage pour mesurer&nbsp; leur impact sur les rayures&nbsp;:<\/span><\/p>\n<table style=\"width: 738px;\">\n<tbody>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Date<\/span><\/strong><\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dur\u00e9e<\/span><\/strong><\/span><\/td>\n<td style=\"width: 190.817px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Position<\/span><\/strong><\/span><\/td>\n<td style=\"width: 124.183px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Ajout poids<\/span><\/strong><\/span><\/td>\n<td style=\"width: 156px; text-align: center;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Temp\u00e9rature<\/span><\/strong><\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">22\/11\/2008<\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2h00<\/span><\/td>\n<td style=\"width: 190.817px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Miroir dessous<\/span><\/td>\n<td style=\"width: 124.183px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1 kg<\/span><\/td>\n<td style=\"width: 156px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">18\u00b0C<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">28\/11\/2008<\/span><\/td>\n<td style=\"width: 103px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2h00<\/span><\/td>\n<td style=\"width: 190.817px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Miroir dessous<\/span><\/td>\n<td style=\"width: 124.183px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">1 kg<\/span><\/td>\n<td style=\"width: 156px; text-align: center;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">20\u00b0C<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Malheureusement, le constat est sans appel&nbsp;: les rayures sont toujours aussi apparentes. Il nous faut donc r\u00e9fl\u00e9chir \u00e0 la meilleure solution pour en venir \u00e0 bout. Deux options sont envisageables&nbsp;:<\/span><\/p>\n<ul>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Revenir en phase de doucissage<\/span><\/li>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Employer une technique de polissage \u00e0 haut rendement<\/span><\/li>\n<\/ul>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La deuxi\u00e8me technique nous a \u00e9t\u00e9 sugg\u00e9r\u00e9e par des opticiens professionnels (JM Lecleire et G. Blanchard) et consiste \u00e0 utiliser des pads en polyur\u00e9thane. Ce type de polissoir permet d\u2019augmenter le rendement d\u2019un facteur 3 environ par-rapport \u00e0 un polissoir classique \u00e0 base de poix. Cette technique ne peut toutefois donner des r\u00e9sultats qu&rsquo;en pr\u00e9sence de rayures pas trop profondes. Il nous faut donc les mesurer. D\u2019apr\u00e8s les praticiens, on peut consid\u00e9rer que la profondeur d\u2019une rayure est du m\u00eame ordre de grandeur que sa largeur. Pour r\u00e9aliser les mesures, nous construisons un microscope de fortune (voir ci-dessous \u00e0 gauche) derri\u00e8re lequel nous prendrons des clich\u00e9s de la surface. Afin de disposer d\u2019un r\u00e9f\u00e9rentiel d\u2019\u00e9chelle de grandeur, nous r\u00e9alisons en pr\u00e9alable un clich\u00e9 du trou calibr\u00e9 de notre \u00e9toile artificielle dont le diam\u00e8tre est connu avec pr\u00e9cision (8 microns). Ensuite, nous comparons cette r\u00e9f\u00e9rence \u00e0 la largeur des rayures mesur\u00e9e sur des clich\u00e9s pris avec un m\u00eame grossissement. Nous obtenons ainsi des largeurs de rayures se situant entre 5 et 10 microns environ (voir ci-dessous \u00e0 droite).<\/span><\/p>\n<table style=\"width: 769px;\">\n<tbody>\n<tr>\n<td style=\"width: 445.5px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060297.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6765\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060297.jpg\" alt=\"\" width=\"1200\" height=\"900\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060297.jpg 3264w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060297-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060297-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060297-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 297.5px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Mesure_largeur_rayure.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6766 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Mesure_largeur_rayure.jpg\" alt=\"\" width=\"1388\" height=\"1550\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Mesure_largeur_rayure.jpg 1388w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Mesure_largeur_rayure-269x300.jpg 269w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Mesure_largeur_rayure-768x858.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Mesure_largeur_rayure-1075x1200.jpg 1075w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">D\u2019apr\u00e8s les sp\u00e9cialistes, la profondeur des rayures semble compatible avec la technique du polissage Polyur\u00e9thane. Nous d\u00e9cidons alors d\u2019opter pour cette solution qui nous permettra \u00e9galement d\u2019explorer une nouvelle technique.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Apr\u00e8s recensement des fournisseurs potentiels, notre choix se porte sur la soci\u00e9t\u00e9 <a href=\"https:\/\/www.mcmaster.com\/\" target=\"_blank\" rel=\"noopener noreferrer\">McMaster-Carr<\/a> &nbsp;aux USA qui propose un disque \u00e0 d\u00e9couper de 30 cm de diam\u00e8tre, 3 mm d\u2019\u00e9paisseur et d\u00e9j\u00e0 impr\u00e9gn\u00e9 d\u2019oxyde de c\u00e9rium. Les morceaux sont d\u00e9coup\u00e9s puis appliqu\u00e9s sur le polissoir de poix 80&nbsp;% (autocollant).<\/span><\/p>\n<table style=\"width: 764px;\">\n<tbody>\n<tr>\n<td style=\"width: 373.983px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_0553-e1525305421268.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6768 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_0553-e1525305421268.jpg\" alt=\"\" width=\"1200\" height=\"800\"><\/a><\/td>\n<td style=\"width: 373.017px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_0555-e1525305581190.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6769 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_0555-e1525305581190.jpg\" alt=\"\" width=\"1200\" height=\"800\"><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Afin d\u2019obtenir le rendement optimal avec cette technique de polissage, il convient d\u2019utiliser des vitesses de plateau machine situ\u00e9es entre 40 et 50 tours\/mn. Pour cela, nous allons utiliser le plateau de la machine pantographe dont nous modifions l\u2019entra\u00eenement (sans r\u00e9ducteur) afin d\u2019atteindre les vitesses requises. Le polissoir sera quant \u00e0 lui maintenu par le bras de la machine double-excentrique. La technique utilis\u00e9e est celle du \u00ab&nbsp;spin polishing&nbsp;\u00bb&nbsp;: D\u00e9bord nul ou faible, tr\u00e8s faible amplitude de va-et-vient et poids rajout\u00e9 de 3 \u00e0 5 kg &nbsp;:<\/span><\/p>\n<p><div class=\"ose-self-hosterd ose-uid-8fbe1b587f5d8b8efa1a093a0b715672 ose-embedpress-responsive\" style=\"width:600px; height:550px; max-height:550px; max-width:100%; display:inline-block;\" data-embed-type=\"document_mp4\"><video controls width=\"600\" height=\"550\"> <source src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2017\/06\/Spin_polishing.mp4\" type=\"video\/mp4\"> <\/video><\/div><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Dans ces conditions, 19 heures ont \u00e9t\u00e9 n\u00e9cessaires entre le 28\/02\/2009 et le 11\/04\/2009 pour venir \u00e0 bout des rayures. Un contr\u00f4le de la surface ainsi obtenue a \u00e9t\u00e9 r\u00e9alis\u00e9 \u00e0 l\u2019appareil de Foucault&nbsp;:<\/span><\/p>\n<table style=\"width: 754px;\">\n<tbody>\n<tr>\n<td style=\"width: 373.367px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6770\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucaukt_1_0804.jpg\" alt=\"\" width=\"800\" height=\"824\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucaukt_1_0804.jpg 295w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucaukt_1_0804-291x300.jpg 291w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<td style=\"width: 360.633px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6771\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Fresnel_1_0804.jpg\" alt=\"\" width=\"772\" height=\"824\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Fresnel_1_0804.jpg 282w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Fresnel_1_0804-281x300.jpg 281w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Il r\u00e9v\u00e8le, sans surprise, un zonage important mais dont on pouvait craindre qu\u2019il soit plus catastrophique. On distingue \u00e9galement nettement les traces en \u00ab&nbsp;spirale&nbsp;\u00bb laiss\u00e9es par le polissoir. Un polissage \u00e0 la poix devrait assez rapidement lisser tous ces d\u00e9fauts.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Afin de pr\u00e9venir autant que possible un nouvel accident li\u00e9 \u00e0 des impuret\u00e9s en phase de polissage, nous avons d\u00e9cid\u00e9 de r\u00e9aliser une enceinte ferm\u00e9e dans laquelle les machines seront install\u00e9es et dont l\u2019acc\u00e8s sera exclusivement r\u00e9serv\u00e9 aux op\u00e9rateurs. Ce volume a \u00e9t\u00e9 r\u00e9alis\u00e9 avec des films de polyane agraf\u00e9s sur un cadre bois&nbsp;:<\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060832.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6772\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060832.jpg\" alt=\"\" width=\"2000\" height=\"1500\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060832.jpg 3264w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060832-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060832-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/P1060832-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le travail se poursuit donc avec le polissoir pleine taille en poix avec une premi\u00e8re session \u00e0 la machine double-excentrique&nbsp;:<\/span><\/p>\n<table>\n<tbody>\n<tr>\n<td style=\"text-align: center;\" width=\"98\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Date<\/span><\/strong><\/td>\n<td style=\"text-align: center;\" width=\"98\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dur\u00e9e<\/span><\/strong><\/td>\n<td style=\"text-align: center;\" width=\"99\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Ajout poids<\/span><\/strong><\/td>\n<td style=\"text-align: center;\" width=\"101\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Temp\u00e9rature<\/span><\/strong><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\" width=\"98\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">11\/04\/2009<\/span><\/td>\n<td style=\"text-align: center;\" width=\"98\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2h00<\/span><\/td>\n<td style=\"text-align: center;\" width=\"99\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2 kg<\/span><\/td>\n<td style=\"text-align: center;\" width=\"101\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">21\u00b0C<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Puis avec la machine pantographe&nbsp;:<\/span><\/p>\n<table>\n<tbody>\n<tr>\n<td style=\"text-align: center;\" width=\"98\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Date<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center;\" width=\"98\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Dur\u00e9e<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center;\" width=\"99\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Ajout poids<\/span><\/strong><\/span><\/td>\n<td style=\"text-align: center;\" width=\"101\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Temp\u00e9rature<\/span><\/strong><\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\" width=\"98\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">09\/05\/2009<\/span><\/td>\n<td style=\"text-align: center;\" width=\"98\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2h20<\/span><\/td>\n<td style=\"text-align: center;\" width=\"99\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2 kg<\/span><\/td>\n<td style=\"text-align: center;\" width=\"101\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">20\u00b0C<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\" width=\"98\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">15\/05\/2009<\/span><\/td>\n<td style=\"text-align: center;\" width=\"98\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2h00<\/span><\/td>\n<td style=\"text-align: center;\" width=\"99\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">2 kg<\/span><\/td>\n<td style=\"text-align: center;\" width=\"101\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">18 \u00e0 19\u00b0C<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Un contr\u00f4le de la forme et de l\u2019\u00e9tat de surface est ensuite r\u00e9alis\u00e9 \u00e0 l\u2019appareil de Foucault&nbsp;:<\/span><\/p>\n<table style=\"width: 758px;\">\n<tbody>\n<tr>\n<td style=\"width: 382.783px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6773 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_1_090610.jpg\" alt=\"\" width=\"901\" height=\"837\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_1_090610.jpg 901w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_1_090610-300x279.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_1_090610-768x713.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<td style=\"width: 353.217px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6774 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Fresnel_1_090610.jpg\" alt=\"\" width=\"908\" height=\"915\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Fresnel_1_090610.jpg 908w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Fresnel_1_090610-150x150.jpg 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Fresnel_1_090610-298x300.jpg 298w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Fresnel_1_090610-768x774.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Fresnel_1_090610-100x100.jpg 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">On constate un lissage important des d\u00e9fauts et un \u00e9tat de surface correct. Au niveau de la forme, le bord est relativement \u00ab&nbsp;plat&nbsp;\u00bb puis on note un changement de pente vers la zone 0,7 et enfin une bosse centrale. Ce contexte permet ainsi d\u2019engager la parabolisation dans de bonnes conditions. La phase de polissage est donc termin\u00e9e. Son bilan global s\u2019\u00e9tablit de la fa\u00e7on suivante&nbsp;:<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\"><strong>30 mai au 28 novembre 2008&nbsp;: <\/strong>Polissage au pleine taille (23h30, machine pantographe)<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\"><strong>28 f\u00e9vrier au 11 avril 2009&nbsp;:<\/strong> Polissage polyur\u00e9thane au 80&nbsp;% (19 h spin polishing)<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\"><strong>9 mai au 15 mai 2009&nbsp;: <\/strong>Polissage au pleine taille (6h20, machine pantographe et double excentrique)<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Soit une dur\u00e9e totale de <strong>48h 50 mn<\/strong><\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L\u2019accident li\u00e9 aux rayures nous aura ainsi co\u00fbt\u00e9 le doublement de la dur\u00e9e de polissage&nbsp;! De quoi m\u00e9diter sur les pr\u00e9cautions extr\u00eames \u00e0 prendre sur la propret\u00e9 &#8230;<\/span><\/p>\n<hr>\n<p>&#8211;<a id=\"o5\"><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 24px;\"><strong><span style=\"font-family: arial, helvetica, sans-serif;\">Parabolisation<\/span><\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Pr\u00e9ambule&nbsp;:<\/span><\/strong><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La m\u00e9thode de parabolisation \u00e0 la machine que nous avons mise en \u0153uvre n\u00e9cessite l&rsquo;utilisation de polissoirs subdiam\u00e9traux de diff\u00e9rentes dimensions. Ceux-ci ont \u00e9galement \u00e9t\u00e9 fabriqu\u00e9s sur une base bois comme celui de pleine taille. La couche sup\u00e9rieure a toutefois \u00e9t\u00e9 r\u00e9alis\u00e9e avec une \u00e9paisseur de m\u00e9dium qui permet une meilleure finition de la surface convexe.<\/span><\/p>\n<table style=\"width: 750px; height: 280px;\">\n<tbody>\n<tr style=\"height: 364.367px;\">\n<td style=\"width: 385px; height: 364.367px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0174-2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6708\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0174-2.jpg\" alt=\"\" width=\"1200\" height=\"866\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0174-2.jpg 2048w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0174-2-300x217.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0174-2-768x554.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/PICT0174-2-1663x1200.jpg 1663w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 364.483px; height: 364.367px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Traces_de_polissage-4.jpg\" alt=\"\" width=\"2048\" height=\"1536\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u200b\u200b\u200b\u200b<span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Pour comprendre les m\u00e9thodes de parabolisation utilis\u00e9es dans cette phase, on se reportera \u00e0 la page consacr\u00e9e \u00e0 <strong><a href=\"http:\/\/gap47.astrosurf.com\/index.php\/technique\/optique-instruments\/optique\/machines-a-polir\/\" target=\"_blank\" rel=\"noopener noreferrer\">l\u2019utilisation des machines<\/a><\/strong><em>.<\/em><\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L\u2019expos\u00e9 ci-dessous se pr\u00e9sente sous la forme d\u2019un carnet de retouches. Il d\u00e9crit \u00e9tape par \u00e9tape les principes de corrections engag\u00e9s ainsi que les r\u00e9sultats obtenus.<\/span><\/p>\n<p><strong><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">D\u00e9tail des sessions r\u00e9alis\u00e9es&nbsp;:<\/span><\/strong><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Afin de d\u00e9finir une strat\u00e9gie de d\u00e9but de parabolisation, des mesures ont \u00e9t\u00e9 pr\u00e9alablement r\u00e9alis\u00e9es \u00e0 l\u2019appareil de Foucault (\u00e9cran \u00e0 \u00e9chancrures de 7 zones)&nbsp;:<\/span><\/p>\n<table style=\"width: 767.6px;\">\n<tbody>\n<tr>\n<td style=\"width: 463px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6710 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session_depart.jpg\" alt=\"\" width=\"379\" height=\"371\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session_depart.jpg 379w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session_depart-300x294.jpg 300w\" sizes=\"auto, (max-width: 379px) 100vw, 379px\" \/><\/td>\n<td style=\"width: 286.6px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Le graphique d\u2019avance des tirages entre zones confirme l\u2019aspect g\u00e9n\u00e9ral observ\u00e9 sur le dernier Foucaultgramme&nbsp;: Une bosse au centre (&nbsp;% n\u00e9gatif) et avance des corrections \u00e0 mi-rayon. La premi\u00e8re intervention va donc consister \u00e0 creuser le centre et \u00e0 \u00ab&nbsp;pousser&nbsp;\u00bb la correction vers les zones p\u00e9riph\u00e9riques.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 463px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6711\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session03.jpg\" alt=\"\" width=\"379\" height=\"373\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session03.jpg 379w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session03-300x295.jpg 300w\" sizes=\"auto, (max-width: 379px) 100vw, 379px\" \/><\/td>\n<td style=\"width: 286.6px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 3&nbsp;&#8211; 12 juin 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">48 mn de session au polissoir 40&nbsp;% sur les zones centrales en variant les amplitudes puis 1h au 60&nbsp;% pour pousser la correction vers le bord. L\u2019intervention a permis de r\u00e9duire la bosse centrale et a fait progresser les tirages sur les 3 derniers tirages. Les \u00e9carts Z3\/Z2 et Z4\/Z3 restent quasiment stables et trop en avance par-rapport aux autres.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table style=\"width: 768px;\">\n<tbody>\n<tr>\n<td style=\"width: 391.817px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.57.29.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6788 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.57.29.png\" alt=\"\" width=\"2184\" height=\"1972\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.57.29.png 2184w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.57.29-300x271.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.57.29-768x693.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.57.29-1329x1200.png 1329w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 358.183px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.58.12.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6789 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.58.12.png\" alt=\"\" width=\"1998\" height=\"1980\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.58.12.png 1998w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.58.12-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.58.12-300x297.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.58.12-768x761.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.58.12-1211x1200.png 1211w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Capture-d\u2019e\u0301cran-2018-05-03-a\u0300-10.58.12-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table style=\"width: 771px;\">\n<tbody>\n<tr>\n<td style=\"width: 465.983px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6712\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session04.jpg\" alt=\"\" width=\"383\" height=\"380\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session04.jpg 383w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session04-150x150.jpg 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session04-300x298.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session04-100x100.jpg 100w\" sizes=\"auto, (max-width: 383px) 100vw, 383px\" \/><\/td>\n<td style=\"width: 289.017px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 4&nbsp;&#8211; 17 juin 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Poursuite de la strat\u00e9gie consistant \u00e0&nbsp; creuser le centre et \u00e0 pousser la correction vers le bord&nbsp;: Surpression au centre \u00e0 la main avec outil 60&nbsp;% (3 tours) puis 2h30 \u00e0 la machine au 60&nbsp;% avec le grandes amplitudes. R\u00e9sultat&nbsp;: la correction du centre a bien progress\u00e9 mais aussi dans une moindre mesure les tirages des zones \u00e0 mi-rayon. Le tirage Z4\/Z3 atteint maintenant 105&nbsp;% ce qui est inqui\u00e9tant.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 465.983px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6713\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session05.jpg\" alt=\"\" width=\"382\" height=\"376\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session05.jpg 382w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session05-300x295.jpg 300w\" sizes=\"auto, (max-width: 382px) 100vw, 382px\" \/><\/td>\n<td style=\"width: 289.017px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 5&nbsp;&#8211; 19 juin 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Afin de r\u00e9duire l\u2019avance de tirage Z4\/Z3, utilisation de courses tangentielles \u00e0 la machine avec le 50&nbsp;%. Le centre du polissoir passe en moyenne sur limite entre les zones 3 et 4. Puis 3 tours avec surpression au centre avec le 50&nbsp;%. Logiquement le centre s\u2019est creus\u00e9 et le tirage Z4\/Z3 a un peu diminu\u00e9. Bizarrement, le dernier tirage (Z7\/Z6) a progress\u00e9 de 14&nbsp;% (probl\u00e8me de mesure au Foucault?).<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 465.983px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6714\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session06_07.jpg\" alt=\"\" width=\"385\" height=\"376\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session06_07.jpg 385w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session06_07-300x293.jpg 300w\" sizes=\"auto, (max-width: 385px) 100vw, 385px\" \/><\/td>\n<td style=\"width: 289.017px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Sessions 6 et 7 &#8211; 20 juin 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Poursuite des courses tangentielles sur zones 3 et 4 mais avec un outil 30&nbsp;% et une charge de 1kg&nbsp;: 30 mn sans offset puis 20 mn avec un offset de 2 cm.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Le tirage Z4\/Z3 a un peu diminu\u00e9 (seulement de 4%). Le rendement des courses tangentielles est faible. Un changement de technique est \u00e0 envisager.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 465.983px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6715\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session08.jpg\" alt=\"\" width=\"380\" height=\"374\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session08.jpg 380w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session08-300x295.jpg 300w\" sizes=\"auto, (max-width: 380px) 100vw, 380px\" \/><\/td>\n<td style=\"width: 289.017px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Session 8 &#8211; 24 juin 2009&nbsp;:<\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Afin de lisser les diff\u00e9rences excessives de tirages, il est d\u00e9cid\u00e9 d\u2019utiliser l\u2019outil pleine taille avec une session de 1h20 \u00e0 la machine pantographe.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">On constate une r\u00e9duction significative de tous les tirage notamment la derni\u00e8re qui \u00e9tait \u00e9galement trop en avance. L\u2019\u00e9cart Z4\/Z3 reste quant \u00e0 lui encore trop important.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 465.983px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6716\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session09.jpg\" alt=\"\" width=\"382\" height=\"357\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session09.jpg 382w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session09-300x280.jpg 300w\" sizes=\"auto, (max-width: 382px) 100vw, 382px\" \/><\/td>\n<td style=\"width: 289.017px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 9 &#8211; 24 juin 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Afin de cibler la r\u00e9duction du tirage Z4\/Z3, il est d\u00e9cid\u00e9 d\u2019utiliser des surpressions entre les milieux des zones 3 et 4. Session de 35 mn \u00e0 l\u2019outil 60&nbsp;%.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">L\u2019intervention a \u00e9t\u00e9 particuli\u00e8rement efficace en faisant chuter le tirage Z4\/Z3 de mani\u00e8re importante (- 62&nbsp;%!). Par contre, les zones int\u00e9rieures ont \u00e9galement \u00e9t\u00e9 impact\u00e9es (Z3\/Z2 chute de 69%). Le contrecoup est l\u2019augmentation des tirages Z5\/Z4 et Z6\/Z5 qui grimpent de 35&nbsp;%&nbsp;!<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 465.983px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6717\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session10.jpg\" alt=\"\" width=\"382\" height=\"373\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session10.jpg 382w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session10-300x293.jpg 300w\" sizes=\"auto, (max-width: 382px) 100vw, 382px\" \/><\/td>\n<td style=\"width: 289.017px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Session 10 &#8211; 26 juin 2009&nbsp;:<\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Afin de lisser les effets brutaux des surpressions pr\u00e9c\u00e9dentes, il est d\u00e9cid\u00e9 d\u2019effectuer une session au pleine taille \u00e0 la machine pantographe pendant 3h15.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">On constate une r\u00e9gression importante des derniers tirages qui s\u2019explique par l\u2019action de l\u2019outil dessus qui attaque plut\u00f4t le bord.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Par diff\u00e9rence, les tirages des zones centrales ont progress\u00e9.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 465.983px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6718\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session11.jpg\" alt=\"\" width=\"382\" height=\"374\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session11.jpg 382w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session11-300x294.jpg 300w\" sizes=\"auto, (max-width: 382px) 100vw, 382px\" \/><\/td>\n<td style=\"width: 289.017px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 11 &#8211; 27 juin 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Poursuite du travail \u00e0 la machine pantographe avec une session de 2h15 \u00e0 l\u2019outil pleine taille.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Malheureusement, le tirage Z4\/Z3 ne bouge quasiment pas. Seuls les deux tirages plus vers le bord diminuent. Le dernier tirage (Z7\/Z6) gagne quant \u00e0 lui 19&nbsp;%<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 465.983px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6719\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session12.jpg\" alt=\"\" width=\"383\" height=\"378\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session12.jpg 383w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session12-300x296.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session12-100x100.jpg 100w\" sizes=\"auto, (max-width: 383px) 100vw, 383px\" \/><\/td>\n<td style=\"width: 289.017px;\"><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\"><strong>Session 12 &#8211; 4 juillet 2009&nbsp;:<\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Il est d\u00e9cid\u00e9 d\u2019insister encore \u00e0 la machine pantographe avec 3h de plus au pleine taille.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">La session a eu relativement peu d\u2019effet. Le tirage Z4\/Z3 reste d\u00e9sesp\u00e9r\u00e9ment fig\u00e9. Les zones centrales gagnent en correction ainsi que, bizarrement le dernier tirage qui prend 18&nbsp;%. Les derniers r\u00e9sultats au pleine taille sont plut\u00f4t incoh\u00e9rents (probl\u00e8me de pressage?).<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 465.983px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6720\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session13.jpg\" alt=\"\" width=\"384\" height=\"378\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session13.jpg 384w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session13-300x295.jpg 300w\" sizes=\"auto, (max-width: 384px) 100vw, 384px\" \/><\/td>\n<td style=\"width: 289.017px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 13 &#8211; 18 juillet&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Face aux r\u00e9sultats assez al\u00e9atoires pr\u00e9c\u00e9dents, il est d\u00e9cid\u00e9 de tenter une technique radicalement diff\u00e9rente&nbsp;: Une session de 1h20 est r\u00e9alis\u00e9e \u00e0 la main, miroir dessus avec des courses classiques de parabolisation de 4\/5 D d\u2019amplitude (voir Texereau). Le r\u00e9sultat obtenu est relativement positif&nbsp;: Les tirages du bord sont remont\u00e9s selon une progression coh\u00e9rente et ceux des zones centrales se sont significativement tass\u00e9s.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><div class=\"ose-youtube ose-uid-7c7416e5d820157e9979abc58b13023a ose-embedpress-responsive\" style=\"width:600px; height:550px; max-height:550px; max-width:100%; display:inline-block;\" data-embed-type=\"Youtube\"><iframe loading=\"lazy\" allowFullScreen=\"true\" title=\"Vid\u00e9o des courses utilis\u00e9es lors de la session 13\" width=\"600\" height=\"550\" src=\"https:\/\/www.youtube.com\/embed\/BNBZsikS-Yk?feature=oembed&color=red&rel=0&controls=1&start=&end=&fs=0&iv_load_policy=0&autoplay=0&mute=0&modestbranding=0&cc_load_policy=1&playsinline=1\" frameborder=\"0\" allow=\"accelerometer; encrypted-media;accelerometer;autoplay;clipboard-write;gyroscope;picture-in-picture clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/div><\/p>\n<table style=\"width: 772px;\">\n<tbody>\n<tr>\n<td style=\"width: 470.983px;\"><img decoding=\"async\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session14.jpg\"><\/td>\n<td style=\"width: 285.017px;\"><span style=\"font-size: 20px;\">&nbsp;<strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 14 &#8211; 4 ao\u00fbt 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Les zones du bord prenant la bonne direction, il est d\u00e9cid\u00e9 de traiter sp\u00e9cifiquement les zones centrales. L\u2019outil 30&nbsp;% est utilis\u00e9 pendant 15 mn avec de faibles amplitudes et un offset allant de 0 \u00e0 15 mm. L\u2019effet escompt\u00e9 est obtenu&nbsp;: les \u00e9carts et progressions de tirages des zones centrales deviennent plus coh\u00e9rents.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 470.983px;\">&nbsp;<img decoding=\"async\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session15.jpg\"><\/td>\n<td style=\"width: 285.017px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 15 &#8211; 4 ao\u00fbt 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">La m\u00eame session que la pr\u00e9c\u00e9dente est r\u00e9alis\u00e9e. La progression des tirages des zones centrales se confirme. Il faut toutefois faire attention \u00e0 ma\u00eetriser la progression du tirage Z3\/Z2.<\/span><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 470.983px;\">&nbsp;<img decoding=\"async\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session16.jpg\"><\/td>\n<td style=\"width: 285.017px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 16 &#8211; 4 ao\u00fbt 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Une session identique est lanc\u00e9e mais pour une dur\u00e9e double (30 mn).<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Les tirages des zones centrales progressent encore. L\u2019\u00e9cart Z3\/Z2 a tendance \u00e0 \u00ab&nbsp;s\u2019envoler&nbsp;\u00bb un peu trop vite.<\/span><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 470.983px;\">&nbsp;<img decoding=\"async\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session17.jpg\"><\/td>\n<td style=\"width: 285.017px;\"><span style=\"font-size: 20px;\">&nbsp;<strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 17 &#8211; 6 ao\u00fbt 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Il convient maintenant de pousser les corrections des zones centrales vers le bord. Pour cela, l\u2019outil 50&nbsp;% est mobilis\u00e9 pendant 1h30 avec des d\u00e9bords de 28 \u00e0 30&nbsp;% et des offsets de 50 \u00e0 62 mm.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Le r\u00e9sultat obtenu est relativement coh\u00e9rent&nbsp;: les \u00e9carts des zones ext\u00e9rieures croissent au d\u00e9triment de ceux des zones centrales. Seule anomalie constat\u00e9e&nbsp;:&nbsp; le tirage Z6\/Z5 diminue.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 470.983px;\">&nbsp;<img decoding=\"async\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session18.jpg\"><\/td>\n<td style=\"width: 285.017px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 18 &#8211; 6 ao\u00fbt 2009&nbsp;:<\/span><\/strong><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Une nouvelle session de 1h15 est lanc\u00e9e \u00e0 l\u2019outil 50&nbsp;% mais en r\u00e9duisant les d\u00e9bords \u00e0 environ 20&nbsp;%. L\u2019id\u00e9e est d\u2019accro\u00eetre la correction un peu avant le bord.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">L\u2019\u00e9volution des \u00e9carts est assez incoh\u00e9rente&nbsp;: Z3\/Z2 et Z5\/Z4 diminuent alors que Z4\/Z3 et Z7\/Z6 augmentent.<\/span><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u200b\u200b\u200b<span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Face aux r\u00e9sultats relativement incoh\u00e9rents des retouches, nous demandons conseil \u00e0 Franck Gri\u00e8re et Carl Zambuto. Ces derniers remarquent le comportement anarchique du polissoir lors des sessions. <\/span><\/p>\n<p><div class=\"ose-self-hosterd ose-uid-3c1d04f167545795c954c9ce120c1775 ose-embedpress-responsive\" style=\"width:600px; height:550px; max-height:550px; max-width:100%; display:inline-block;\" data-embed-type=\"document_mp4\"><video controls width=\"600\" height=\"550\"> <source src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2017\/06\/Polissoir_valse.mp4\" type=\"video\/mp4\"> <\/video><\/div><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Ils nous conseillent de gaufrer les carr\u00e9s de poix afin d&rsquo;obtenir une adh\u00e9rence homog\u00e8ne (voir photo ci-apr\u00e8s). A partir de la session 19, nous allons donc gaufrer syst\u00e9matiquement nos polissoirs. Leur comportement redevient alors normal (rotation similaire \u00e0 celle du miroir) et les effets des retouches tendent vers une bien meilleure coh\u00e9rence.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6733\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF0020.jpg\" alt=\"\" width=\"1200\" height=\"1200\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF0020.jpg 1024w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF0020-150x150.jpg 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF0020-300x300.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF0020-768x768.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF0020-100x100.jpg 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/p>\n<p>&nbsp;<\/p>\n<table style=\"width: 801px;\">\n<tbody>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6734\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session19.jpg\" alt=\"\" width=\"385\" height=\"375\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session19.jpg 385w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session19-300x292.jpg 300w\" sizes=\"auto, (max-width: 385px) 100vw, 385px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 19 &#8211; 12 septembre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">L\u2019id\u00e9e est de faire remonter les tirages Z5\/Z4 et Z6\/Z5 qui sont tr\u00e8s en retard, notamment par-rapport \u00e0 Z7\/Z6. Pour cela il est proc\u00e9d\u00e9 \u00e0 une \u00ab&nbsp;sweep technique&nbsp;\u00bb cibl\u00e9e sur la zone 5 avec l\u2019otil 50&nbsp;%. Le d\u00e9bord est donc contraint \u00e0 6&nbsp;% et les offsets varient de 0 \u00e0 40 mm. Dur\u00e9e de la session&nbsp;: 1h.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Le r\u00e9sultat est assez d\u00e9cevant&nbsp;: Seul l\u2019\u00e9cart Z5\/Z4 augmente significativement (+10%)&nbsp; Le tirage Z6\/Z5 reste toujours bien trop en retrait.<\/span><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6735\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session20.jpg\" alt=\"\" width=\"389\" height=\"380\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session20.jpg 389w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session20-300x293.jpg 300w\" sizes=\"auto, (max-width: 389px) 100vw, 389px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 20 &#8211; 18 septembre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Engagement d\u2019une session plus classique au 50&nbsp;% pendant 1 h avec des d\u00e9bords vari\u00e9s plus faibles que pr\u00e9c\u00e9demment (0 \u00e0 9%) et des offsets de 0 \u00e0 10 mm. Le but est de pousser l\u2019exc\u00e8s de correction des zones centrales vers celles situ\u00e9es plus vers l\u2019ext\u00e9rieur.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Les tirages Z5\/Z4 et Z6\/Z5 ont effectivement progress\u00e9 mais seulement l\u00e9g\u00e8rement. Par contre les tirages pr\u00e9c\u00e9dents ont beaucoup plus progress\u00e9 ce qui n\u2019\u00e9tait pas le but.<\/span><\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6736\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session21.jpg\" alt=\"\" width=\"388\" height=\"381\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session21.jpg 388w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session21-300x295.jpg 300w\" sizes=\"auto, (max-width: 388px) 100vw, 388px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><span style=\"font-family: times\\ new\\ roman, times, serif;\">&nbsp;<\/span><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 21 &#8211; 26 septembre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Nous allons tenter de repousser les corrections centrales vers le bord avec un outil 60&nbsp;% et une \u00ab&nbsp;sweep technique&nbsp;\u00bb aux d\u00e9bords contraints \u00e0 14&nbsp;% (pour pr\u00e9server le dernier tirage Z7\/Z6) et un offset progressant de 0 \u00e0 31 mm (dur\u00e9e&nbsp;: 1h).<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Une relation de cause \u00e0 effet est enfin au rendez-vous&nbsp;: Les tirages au centre se tassent au profit des zones plus p\u00e9riph\u00e9riques tout en limitant l\u2019impact sur Z7\/Z6.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6737\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session22.jpg\" alt=\"\" width=\"390\" height=\"385\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session22.jpg 390w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session22-300x296.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session22-100x100.jpg 100w\" sizes=\"auto, (max-width: 390px) 100vw, 390px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 22 &#8211; 2 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">On ne change pas une technique qui gagne&nbsp;! La session pr\u00e9c\u00e9dente est donc r\u00e9it\u00e9r\u00e9e en poussant encore un peu plus les offsets (jusqu\u2019\u00e0 39 mm cette fois-ci).<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">L\u00e0 aussi le r\u00e9sultat est coh\u00e9rent&nbsp;: les tirages avant le dernier (Z6\/Z5 et Z5\/Z4) progressent alors que plus vers le centre les corrections s\u2019att\u00e9nuent. Le dernier tirage (Z7\/Z6) reste quant \u00e0 lui plut\u00f4t stable. La strat\u00e9gie semble enfin payer&nbsp;!<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">&nbsp;<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6738\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session23.jpg\" alt=\"\" width=\"391\" height=\"379\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session23.jpg 391w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session23-300x291.jpg 300w\" sizes=\"auto, (max-width: 391px) 100vw, 391px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 23 &#8211; 3 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Nouvelle session strictement identique \u00e0 la pr\u00e9c\u00e9dente.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Le seul \u00e9cart qui progresse est Z6\/Z5&nbsp;: \u00e7a tombe bien, c\u2019est celui qui \u00e9tait le plus en retard&nbsp;! Les tirages des zones plus au centre continuent \u00e0 se tasser. Le profil g\u00e9n\u00e9ral du graphique tend vers une configuration id\u00e9ale&nbsp;: augmentation progressive des \u00e9carts en s\u2019\u00e9loignant du centre sans palier excessif.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">&nbsp;<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6739\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session24.jpg\" alt=\"\" width=\"393\" height=\"384\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session24.jpg 393w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session24-300x293.jpg 300w\" sizes=\"auto, (max-width: 393px) 100vw, 393px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 24 &#8211; 9 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Une session plus classique est tent\u00e9e pour r\u00e9enclencher de la correction au bord. Toujours au 60&nbsp;% pendant 1h mais en variant les d\u00e9bords de 17 \u00e0 31&nbsp;%. les offsets quant \u00e0 eux varient de 3 \u00e0 23 mm.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">On obtient une progression significative du tirage au bord (avec un bond de 20&nbsp;%!).<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Attention \u00e0 ne pas laisser partir la correction au bord trop rapidement \u2026<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">&nbsp;<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6740\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session25.jpg\" alt=\"\" width=\"385\" height=\"384\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session25.jpg 385w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session25-150x150.jpg 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session25-300x300.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session25-100x100.jpg 100w\" sizes=\"auto, (max-width: 385px) 100vw, 385px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><span style=\"font-family: times\\ new\\ roman, times, serif;\">&nbsp;<\/span><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 25 &#8211; 10 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Cette session sera mixte&nbsp;: 45 mn au 60&nbsp;% en \u00ab&nbsp;sweep technique&nbsp;\u00bb avec d\u00e9bord contraint \u00e0 14&nbsp;% et 20 mn au 30% sur les zones centrales.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">L\u2019\u00e9cart Z6\/Z5 ne progresse que faiblement et le Z7\/Z6 au bord se tasse un peu. Le petit outil a fait beaucoup progresser le tirage au centre.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6741\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session26.jpg\" alt=\"\" width=\"391\" height=\"383\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session26.jpg 391w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session26-300x294.jpg 300w\" sizes=\"auto, (max-width: 391px) 100vw, 391px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 26 &#8211; 14 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Nouvelle session mixte&nbsp;: D\u2019abord au 30&nbsp;% pour creuser le centre pendant 10 mn puis une \u00ab&nbsp;sweep technique&nbsp;\u00bb au 50&nbsp;% (pour mieux cibler Z6\/Z5 sans impacter Z7\/Z6) avec d\u00e9bord contraint \u00e0 15&nbsp;% pendant 45 mn.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Le r\u00e9sultat est satisfaisant&nbsp;: Z6\/Z5 progresse bien (+ 18%) alors que Z7\/Z6 reste relativement stable (progression contenue \u00e0 5%). La correction au centre a progress\u00e9 comme souhait\u00e9.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">&nbsp;<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6742\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session27.jpg\" alt=\"\" width=\"382\" height=\"349\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session27.jpg 382w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session27-300x274.jpg 300w\" sizes=\"auto, (max-width: 382px) 100vw, 382px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 27 &#8211; 14 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Session de 20 mn au 40% pour augmenter&nbsp; les \u00e9carts des zones au centre.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Les r\u00e9sultats montrent effectivement une progression d&rsquo;environ 10% des 3 premiers tirages. Le tirage Z6\/Z5 r\u00e9gresse un petit peu.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">&nbsp;<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6743\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session28.jpg\" alt=\"\" width=\"392\" height=\"351\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session28.jpg 392w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session28-300x269.jpg 300w\" sizes=\"auto, (max-width: 392px) 100vw, 392px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><span style=\"font-family: times\\ new\\ roman, times, serif;\">&nbsp;<\/span><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 28 &#8211; 16 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Session au 50% pendant 30 mn pour tenter d&rsquo;augmenter les correction des zones interm\u00e9diaires.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Les r\u00e9sultats montrent un impact sur Z3\/Z2 et Z4\/Z3 (+ 18% environ) mais Z5\/Z4 n&rsquo;augmente que tr\u00e8s faiblement.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6744\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session29.jpg\" alt=\"\" width=\"389\" height=\"357\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session29.jpg 389w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session29-300x275.jpg 300w\" sizes=\"auto, (max-width: 389px) 100vw, 389px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 29 &#8211; 21 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Nouvelle session au 50% pendant 20 mn mais en poussant plus les d\u00e9bords pour corriger plus loin du centre que la session pr\u00e9c\u00e9dente (d\u00e9bords entre -3 et -5%, offsets de 3 \u00e0 20 mm).<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">La strat\u00e9gie a port\u00e9 ses fruits&nbsp;: Le tirage de Z5\/Z4 augmente ainsi que Z4\/Z3 dans les m\u00eames proportions (environ + 10%).<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">&nbsp;<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6745\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session30.jpg\" alt=\"\" width=\"384\" height=\"356\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session30.jpg 384w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session30-300x278.jpg 300w\" sizes=\"auto, (max-width: 384px) 100vw, 384px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><span style=\"font-family: times\\ new\\ roman, times, serif;\">&nbsp;<\/span><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 30 &#8211; 21 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Session mixte pour augmenter la correction des zones interm\u00e9diaires&nbsp;: 20 mn au 30% pour creuser le centre puis 20 mn au 50% pour pousser la correction vers l&rsquo;ext\u00e9rieur.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Les r\u00e9sultats montrent en effet que les 3 premiers \u00e9carts en partant du centre progressent. Le tirage Z5\/Z4 reste malgr\u00e9 tout un peu en retrait.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6746\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session31.jpg\" alt=\"\" width=\"387\" height=\"348\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session31.jpg 387w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session31-300x270.jpg 300w\" sizes=\"auto, (max-width: 387px) 100vw, 387px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 31 &#8211; 23 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Pour mieux cibler la correction Z5\/Z4, r\u00e9alisation d&rsquo;une retouche \u00e0 la main au polissoir 50% par surpression du bord entre&nbsp; l&rsquo;ext\u00e9rieur de la zone 2 et le milieu de la zone 4 (dur\u00e9e&nbsp;: 7 mn).<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Le graphique montre effectivement une progression de Z5\/Z4 ainsi que Z4\/Z3.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">&nbsp;<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6747\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session32.jpg\" alt=\"\" width=\"391\" height=\"356\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session32.jpg 391w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session32-300x273.jpg 300w\" sizes=\"auto, (max-width: 391px) 100vw, 391px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><span style=\"font-family: times\\ new\\ roman, times, serif;\">&nbsp;<\/span><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 32 &#8211; 28 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Il s&rsquo;agit de remonter le&nbsp; tirage du bord (Z7\/Z6). Pour cela, une \u00ab&nbsp;sweep technique&nbsp;\u00bb est toute indiqu\u00e9e avec un d\u00e9bord contraint \u00e0 26% et des offsets variant de 0 \u00e0 30 mn pendant 20 mn. Au pr\u00e9alable, on aura creus\u00e9 le centre au 30% pendant 9 mn.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Pari r\u00e9ussi&nbsp;: Le graphique montre bien une remont\u00e9e de Z7\/Z6 (environ 8%). Le centre a gagn\u00e9 \u00e9galement en correction.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6748\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session33.jpg\" alt=\"\" width=\"396\" height=\"354\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session33.jpg 396w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session33-300x268.jpg 300w\" sizes=\"auto, (max-width: 396px) 100vw, 396px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><span style=\"font-family: times\\ new\\ roman, times, serif;\">&nbsp;<\/span><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 33 &#8211; 30 octobre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Le but est de faire encore progresser les corrections en dessous de la zone 5. Une session mixte est r\u00e9alis\u00e9e dans ce but avec 8 mn au 40% suivies de 12 mn au 50% avec des d\u00e9bords entre -4 et -8% et des offsets variant de 3 \u00e0 20 mm.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Tous les \u00e9carts int\u00e9rieurs progressent sauf Z7\/Z6 au bord et Z2\/Z1 au centre. Le tirage Z3\/Z2 augmente m\u00eame de 15%.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 512.267px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6749\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session34.jpg\" alt=\"\" width=\"393\" height=\"355\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session34.jpg 393w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Session34-300x271.jpg 300w\" sizes=\"auto, (max-width: 393px) 100vw, 393px\" \/><\/td>\n<td style=\"width: 270.733px;\"><span style=\"font-size: 20px;\"><span style=\"font-family: times\\ new\\ roman, times, serif;\">&nbsp;<\/span><strong><span style=\"font-family: times\\ new\\ roman, times, serif;\">Session 34 &#8211; 4 novembre 2009&nbsp;:<\/span><\/strong><\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Il reste \u00e0 remonter les tirages au centre. Pour cela, une session mixte est mise en \u0153uvre avec 9 mn au 30% pour agir sur l\u2019extr\u00eame centre et 10 mn au 50% pour traiter la zone plus \u00e0 l&rsquo;ext\u00e9rieur.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Le graphique montre des plots assez proches de 100% notamment sur la moiti\u00e9 ext\u00e9rieure l\u00e0 o\u00f9 c&rsquo;est le plus sensible.<\/span><\/p>\n<p><span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">Des contr\u00f4les plus complets confirmeront l&rsquo;atteinte finale des objectifs.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Bilan de la parabolisation&nbsp;:<\/span><\/strong><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La phase de parabolisation n&rsquo;a pas \u00e9t\u00e9 un long fleuve tranquille&nbsp;! Elle a \u00e9t\u00e9 l&rsquo;occasion d&rsquo;un apprentissage des techniques d&rsquo;asph\u00e9risation \u00e0 la machine. La progression de la forme a d&rsquo;abord \u00e9t\u00e9 quelque-peu chaotique. Elle est devenue ensuite beaucoup plus coh\u00e9rente \u00e0 partir du moment o\u00f9 nous avons gaufr\u00e9 et correctement press\u00e9 les outils. L&rsquo;animation ci-dessous retrace l&rsquo;avanc\u00e9e des sessions dans cette derni\u00e8re phase o\u00f9 l&rsquo;on peut voir une progression relativement conforme aux principes fix\u00e9s par la th\u00e9orie (voir page \u00ab&nbsp;<a href=\"http:\/\/gap47.astrosurf.com\/index.php\/principes-dutilisation-des-machines-a-polir\/\" target=\"_blank\" rel=\"noopener noreferrer\">Principes d&rsquo;utilisation des machines \u00e0 polir<\/a>&nbsp;\u00bb).<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6752\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Evolution_corrections.gif\" alt=\"\" width=\"600\" height=\"600\"><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Enfin, nous tenons particuli\u00e8rement \u00e0 remercier Franck Gri\u00e8re et Carl Zambuto pour les pr\u00e9cieux conseils qu&rsquo;ils nous ont d\u00e9livr\u00e9s dans l&rsquo;utilisation des machines \u00e0 polir.<\/span><\/p>\n<hr>\n<p>&#8211;<a id=\"o6\"><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 24px;\"><strong><span style=\"font-family: arial, helvetica, sans-serif;\">Contr\u00f4les<\/span><\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Afin d&rsquo;\u00e9valuer le plus objectivement possible la qualit\u00e9 du miroir, nous avons crois\u00e9 plusieurs m\u00e9thodes de contr\u00f4le adapt\u00e9es \u00e0 diff\u00e9rents crit\u00e8res&nbsp;:<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Aspect g\u00e9n\u00e9ral de la forme&nbsp;:<\/span><\/strong><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L&rsquo;aspect g\u00e9n\u00e9ral observ\u00e9 \u00e0 l&rsquo;appareil de Foucault r\u00e9v\u00e8le une forme qui para\u00eet douce et sans zonage apparent. Le Ronchigramme confirme cette impression (les courbes de la trame montrent des zones bien raccord\u00e9es, sans changement brusque de pente). Seule une petite zone centrale d\u2019environ 80 mm de diam\u00e8tre reste \u00ab&nbsp;plate&nbsp;\u00bb (sph\u00e9rique). Ce d\u00e9faut sera ignor\u00e9 car il se trouve occult\u00e9 par le futur miroir secondaire de 110 mm de petit axe.<\/span><\/p>\n<table style=\"width: 801px;\">\n<tbody>\n<tr>\n<td style=\"width: 252px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6791 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C1.png\" alt=\"\" width=\"956\" height=\"952\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C1.png 956w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C1-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C1-300x300.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C1-768x765.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C1-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 251.083px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C2.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6792\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C2.png\" alt=\"\" width=\"956\" height=\"952\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C2.png 954w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C2-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C2-300x300.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C2-768x765.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C2-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 253.917px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C3.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6793\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C3.png\" alt=\"\" width=\"956\" height=\"952\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C3.png 948w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C3-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C3-300x300.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C3-768x765.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C3-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 252px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C4.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6794 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C4.png\" alt=\"\" width=\"946\" height=\"952\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C4.png 946w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C4-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C4-298x300.png 298w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C4-768x773.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C4-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 251.083px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C5.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6795\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C5.png\" alt=\"\" width=\"952\" height=\"952\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C5.png 944w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C5-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C5-300x300.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C5-768x768.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C5-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 253.917px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C6.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6796\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C6.png\" alt=\"\" width=\"944\" height=\"952\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C6.png 942w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C6-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C6-297x300.png 297w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C6-768x775.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C6-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 252px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C7.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6797\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C7.png\" alt=\"\" width=\"956\" height=\"952\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C7.png 946w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C7-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C7-300x300.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C7-768x765.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C7-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 251.083px;\">&nbsp;<\/td>\n<td style=\"width: 253.917px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C8.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6798\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C8.png\" alt=\"\" width=\"936\" height=\"952\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C8.png 954w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C8-295x300.png 295w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C8-768x781.png 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Analyse du bord&nbsp;:<\/span><\/strong><\/p>\n<table style=\"width: 806px;\">\n<tbody>\n<tr>\n<td style=\"width: 234.867px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6800 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C9.png\" alt=\"\" width=\"864\" height=\"930\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C9.png 864w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C9-279x300.png 279w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C9-768x827.png 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<td style=\"width: 253.133px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6801 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C10.png\" alt=\"\" width=\"950\" height=\"932\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C10.png 950w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C10-300x294.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C10-768x753.png 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<td style=\"width: 281px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6802 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C11.png\" alt=\"\" width=\"1056\" height=\"924\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C11.png 1056w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C11-300x263.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C11-768x672.png 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table style=\"width: 809.1px;\">\n<tbody>\n<tr>\n<td style=\"width: 564px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C12.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignright wp-image-6803 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C12.png\" alt=\"\" width=\"1420\" height=\"1420\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C12.png 1420w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C12-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C12-300x300.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C12-768x768.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C12-1200x1200.png 1200w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C12-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 239.1px;\"><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les franges de Fresnel ne montrent pas d\u2019inflexion \u00e0 l\u2019approche du bord. Couteau ferm\u00e9 au rayon de courbure de la zone externe, on peut observer l\u2019anneau de Rayleigh sans discontinuit\u00e9 sur la circonf\u00e9rence totale du miroir (photo \u00e0 gauche). Les d\u00e9fauts de bord ont par chance \u00e9t\u00e9 \u00e9vit\u00e9s.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\"><strong>Analyse du mamelonnage&nbsp;<\/strong>:<\/span><\/p>\n<table style=\"width: 866px;\">\n<tbody>\n<tr>\n<td style=\"width: 430.067px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C13.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6804 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C13.png\" alt=\"\" width=\"1376\" height=\"1374\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C13.png 1376w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C13-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C13-300x300.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C13-768x767.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C13-1202x1200.png 1202w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C13-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 426.933px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C14.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6805 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C14.png\" alt=\"\" width=\"1380\" height=\"1382\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C14.png 1380w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C14-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C14-300x300.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C14-768x769.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C14-1198x1200.png 1198w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C14-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La photo de gauche montre un Foucaulgramme dont la coupe a \u00e9t\u00e9 r\u00e9alis\u00e9e avec une lame de phase. Ce test passe pour \u00eatre particuli\u00e8rement sensible aux d\u00e9fauts de mamelonnage. La douceur des formes montre que ce d\u00e9faut est peu pr\u00e9sent. Le Foucaulgramme de droite, r\u00e9alis\u00e9 au rayon de courbure du centre du miroir, montre un l\u00e9ger mamelonnage sur une surface d\u2019environ 80 mm de diam\u00e8tre, r\u00e9sidu de l\u2019action un peu trop agressive du petit polissoir (120 mm de diam\u00e8tre). Comme indiqu\u00e9 pr\u00e9c\u00e9demment, ce d\u00e9faut est \u00e0 ignorer car occult\u00e9 par le secondaire.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\"><strong>Analyse de l\u2019\u00e9tat de surface&nbsp;<\/strong>:<\/span><\/p>\n<p><span style=\"font-size: 20px; font-family: times\\ new\\ roman, times, serif;\">&nbsp;<a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C15.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-6807\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C15.png\" alt=\"\" width=\"2500\" height=\"2400\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C15.png 1892w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C15-300x288.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C15-768x737.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C15-1250x1200.png 1250w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Une premi\u00e8re analyse a \u00e9t\u00e9 r\u00e9alis\u00e9e avec une lame de phase de densit\u00e9 1,5 environ r\u00e9alis\u00e9e sur un n\u00e9gatif photo (voir principe <a href=\"http:\/\/www.astrosurf.com\/tests\/contrast\/lame.htm\" target=\"_blank\" rel=\"noopener noreferrer\">ici<\/a>). Le Lyotgramme ci-dessus n\u2019a subi aucun traitement. Il semble r\u00e9v\u00e9ler un \u00e9tat de surface de bonne qualit\u00e9. On peut toutefois noter une l\u00e9g\u00e8re structure dont la trame est \u00e0 mettre en corr\u00e9lation avec celle du treillis ayant servi \u00e0 effectuer le gaufrage des polissoirs. Pour \u00e9viter ce ph\u00e9nom\u00e8ne, il aurait \u00e9t\u00e9 souhaitable de finir le miroir avec un polissoir aux carr\u00e9s lisses. Cette analyse bien qu&rsquo;uniquement qualitative, permet d\u00e9j\u00e0 de se faire une id\u00e9e globale de l&rsquo;\u00e9tat de surface.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Afin de quantifier les d\u00e9fauts de rugosit\u00e9 du miroir, nous avons pu nous procurer une lame de phase calibr\u00e9e de densit\u00e9 2,5 r\u00e9alis\u00e9e par un d\u00e9p\u00f4t sous vide d&rsquo;une couche de chrome sur une lame de microscope <\/span><span style=\"font-family: times new roman, times, serif; font-size: 20px;\">(fabrication <a href=\"https:\/\/bigowlbinoscope.fr\/\" target=\"_blank\" rel=\"noopener noreferrer\">Bigowlbinoscope<\/a>). <\/span><span style=\"font-family: times new roman, times, serif; font-size: 20px;\">Le nouveau clich\u00e9 ci-dessous, bien qu&rsquo;imparfait (vignetage, poussi\u00e8res) a permis d\u2019\u00e9valuer l&rsquo;amplitude des d\u00e9fauts de rugosit\u00e9 \u00e0 l&rsquo;aide de la formule propos\u00e9e par <a href=\"http:\/\/www.astrosurf.com\/tests\/articles\/defauts\/defauts.htm#6\" target=\"_blank\" rel=\"noopener noreferrer\">Bernard Lyot<\/a> et reprise par <a href=\"https:\/\/bigowlbinoscope.fr\/prestations\/lame-a-contraste-de-phase\/?v=11aedd0e4327\" target=\"_blank\" rel=\"noopener noreferrer\">Terence Pelletier<\/a>.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSC_0245_fenetre.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-7205 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSC_0245_fenetre.jpg\" alt=\"\" width=\"2659\" height=\"2701\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSC_0245_fenetre.jpg 2659w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSC_0245_fenetre-295x300.jpg 295w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSC_0245_fenetre-768x780.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSC_0245_fenetre-1181x1200.jpg 1181w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/span><\/p>\n<p><span style=\"font-family: times new roman, times, serif; font-size: 20px;\">On retrouve bien les cellules de micromamelonnage sur une fr\u00e9quence spatiale d&rsquo;environ 4 mm qui peut \u00eatre imput\u00e9e aux traces laiss\u00e9es par le treillis utilis\u00e9 pour gaufrer le polissoir. L&rsquo;amplitude de ces d\u00e9fauts a \u00e9t\u00e9 \u00e9valu\u00e9e \u00e0 environ 3 Angstr\u00f6ms RMS sur l&rsquo;onde. Ce miroir n&rsquo;entre donc pas dans les crit\u00e8res stricts pouvant le qualifier de \u00ab&nbsp;superpoli&nbsp;\u00bb (maxi 2&nbsp; Angstr\u00f6ms RMS sur l&rsquo;onde) mais sa diffusion sur les objets brillants sera tr\u00e8s limit\u00e9e.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\"><strong>Analyse de l\u2019astigmatisme&nbsp;:<\/strong><\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C16.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6808\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C16.png\" alt=\"\" width=\"3500\" height=\"1124\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C16.png 2934w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C16-300x96.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C16-768x247.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C16-2000x642.png 2000w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les startest ci-dessus ont \u00e9t\u00e9 r\u00e9alis\u00e9s au centre de courbure avec une \u00e9toile artificielle constitu\u00e9e d\u2019un trou calibr\u00e9 de 8 microns de diam\u00e8tre (Edmund Optics). L\u2019analyse de la circularit\u00e9 des figures est un moyen rapide permettant d&rsquo;\u00e9valuer l&rsquo;astigmatisme d&rsquo;ensemble. Dans le cas pr\u00e9sent, on peut conclure que ce d\u00e9faut se situe largement dans les tol\u00e9rances. On peut par-ailleurs noter la pr\u00e9sence d\u2019un l\u00e9ger trefoil \u00e0 priori d\u00fb aux appuis lat\u00e9raux du support de contr\u00f4le. <\/span><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Une analyse plus fine de ces d\u00e9fauts sera effectu\u00e9e \u00e0 l&rsquo;interf\u00e9rom\u00e8tre. <\/span><\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Quantification des d\u00e9fauts du front d&rsquo;onde \u00e9mergeant&nbsp;:<\/span><\/strong><\/p>\n<p><em><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Test au Foucault d&rsquo;atelier&nbsp;:<\/span><\/em><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C17.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6809\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C17.png\" alt=\"\" width=\"3400\" height=\"2302\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C17.png 2570w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C17-300x203.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C17-768x520.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C17-1772x1200.png 1772w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La premi\u00e8re s\u00e9rie de tests a \u00e9t\u00e9 effectu\u00e9e au traditionnel appareil de Foucault d&rsquo;atelier (mod\u00e8le \u00e0 source fixe). L&rsquo;\u00e9cran \u00e0 \u00e9chancrures de Couder comporte 7 zones. Les r\u00e9sultats ont \u00e9t\u00e9 crois\u00e9s sur les mesures r\u00e9alis\u00e9es en aveugle par deux testeurs.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les profils ont \u00e9t\u00e9 \u00e9tudi\u00e9s sur deux m\u00e9ridiennes tourn\u00e9es \u00e0 90\u00b0 l&rsquo;une par-rapport \u00e0 l&rsquo;autre.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les \u00bd profils de l&rsquo;onde pour chaque m\u00e9ridienne se pr\u00e9sentent de la fa\u00e7on suivante&nbsp;:<\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C18.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6810 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C18.png\" alt=\"\" width=\"2172\" height=\"746\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C18.png 2172w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C18-300x103.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C18-768x264.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C18-2000x687.png 2000w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><br \/>\n<span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">M\u00e9ridienne 1 : <span style=\"color: #000000;\">Pour acc\u00e9der au bulletin de contr\u00f4le complet de la m\u00e9ridienne 1, <a style=\"color: #000000;\" href=\"http:\/\/www.astrosurf.com\/gap47\/T400\/Optique\/controle\/Bulettin_meridien1.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">cliquer ici<\/a><\/span><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C19.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6811 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C19.png\" alt=\"\" width=\"2180\" height=\"752\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C19.png 2180w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C19-300x103.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C19-768x265.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C19-2000x690.png 2000w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><br \/>\n<span style=\"font-family: 'times new roman', times, serif; font-size: 20px;\">M\u00e9ridienne 2 : <span style=\"color: #000000;\">Pour acc\u00e9der au bulletin de contr\u00f4le complet de la m\u00e9ridienne 2, <a href=\"http:\/\/www.astrosurf.com\/gap47\/T400\/Optique\/controle\/Bulettin_meridien2.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">cliquer ici<\/a><\/span><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><em><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Test \u00e0 l&rsquo;interf\u00e9rom\u00e8tre de Bath&nbsp;:<\/span><\/em><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Afin d&rsquo;effectuer les premiers tests, nous avons fabriqu\u00e9 sommairement un premier appareil bas\u00e9 sur un pointeur laser vert de qualit\u00e9 courante (532 nm de longueur d&rsquo;onde) et de composants optiques achet\u00e9s chez Surplus Shed (cube s\u00e9parateur de 15 mm, miroir plan de 20 mm et lentille biconvexe de 10 mm de longueur focale)&nbsp;:<\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C20.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6813\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C20.png\" alt=\"\" width=\"2000\" height=\"1494\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C20.png 1296w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C20-300x224.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C20-768x574.png 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Malgr\u00e9 notre manque d&rsquo;exp\u00e9rience, nous n&rsquo;avons pas eu de mal \u00e0 obtenir assez rapidement des interf\u00e9rogrammes de bonne qualit\u00e9 (la suite montrera que la chance y \u00e9tait pour beaucoup) :<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6814 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C21.png\" alt=\"\" width=\"1290\" height=\"1290\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C21.png 1290w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C21-150x150.png 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C21-300x300.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C21-768x768.png 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C21-1200x1200.png 1200w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/C21-100x100.png 100w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les premi\u00e8res tentatives d&rsquo;analyse de ces interf\u00e9rogrammes ont \u00e9t\u00e9 r\u00e9alis\u00e9es sur le logiciel OpenFringe via la m\u00e9thode de tra\u00e7age des franges. Face \u00e0 notre manque de ma\u00eetrise de cet outil, nous avons fait appel \u00e0 l&rsquo;assistance de Charles Rydel puis Fr\u00e9d\u00e9ric Jabet. Les r\u00e9sultats obtenus \u00e0 l&rsquo;aide de deux logiciels diff\u00e9rents convergent&nbsp;:<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6815 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Analyse_Bath_Jabet_2.png\" alt=\"\" width=\"903\" height=\"585\"><br \/>\n<span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px; color: #008000;\"><em>Logiciel AtmosFringe&nbsp;: Rapport de Strelh = 62%<\/em><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6816 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Analyse_Bath_Jabet_1.png\" alt=\"\" width=\"1000\" height=\"717\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Analyse_Bath_Jabet_1.png 1000w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Analyse_Bath_Jabet_1-300x215.png 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Analyse_Bath_Jabet_1-768x551.png 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><br \/>\n<span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px; color: #008000;\"><em>Logiciel OpenFringe&nbsp;: Rapport de Strelh = 60%<\/em><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">A l&rsquo;\u00e9vidence, les r\u00e9sultats des tests interf\u00e9rom\u00e9triques sont bien moins flatteurs que ceux obtenus au Foucault d&rsquo;atelier. Le choc est rude&nbsp;! En l&rsquo;\u00e9tat, la qualit\u00e9 du miroir n&rsquo;atteint pas les crit\u00e8res que nous nous \u00e9tions fix\u00e9s&nbsp;:<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L&rsquo;aberration sph\u00e9rique est particuli\u00e8rement prononc\u00e9e et de type sous-correction. <\/span><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">On note par-ailleurs un astigmatisme important. Son orientation laisse toutefois supposer qu&rsquo;il pourrait \u00eatre caus\u00e9 par la pliure du miroir sur son support de contr\u00f4le (position verticale, maintien du bord par sangle). Le bord relev\u00e9 \u00e0 11h est peut-\u00eatre \u00e9galement d\u00fb \u00e0 l&rsquo;appui du haut du miroir sur le support de contr\u00f4le.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Ce premier contact avec le test interf\u00e9rom\u00e9trique nous fait prendre conscience de son extr\u00eame sensibilit\u00e9 et de la rigueur sans faille qui doit nous guider pour aboutir \u00e0 des r\u00e9sultats auxquels on peut se fier avec une relative certitude. <\/span><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Nous d\u00e9cidons en cons\u00e9quence d&rsquo;agir sur plusieurs plans afin de fiabiliser au maximum le test interf\u00e9rom\u00e9trique&nbsp;:<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Am\u00e9lioration du banc de contr\u00f4le&nbsp;:<\/span><\/strong><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/banc-controle-2015.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6818 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/banc-controle-2015.jpg\" alt=\"\" width=\"1562\" height=\"1462\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/banc-controle-2015.jpg 1562w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/banc-controle-2015-300x281.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/banc-controle-2015-768x719.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/banc-controle-2015-1282x1200.jpg 1282w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Le miroir sera test\u00e9 en position l\u00e9g\u00e8rement inclin\u00e9e. Le miroir reposera sur un barillet int\u00e9gr\u00e9 (9 points sur 3 triangles) et sera support\u00e9 sur sa tranche par 4 roulements (solidaires de 2 balanciers).<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Afin de limiter la turbulence li\u00e9e aux mouvements d&rsquo;air lors des contr\u00f4les, un tunnel est r\u00e9alis\u00e9 \u00e0 l&rsquo;aide d&rsquo;une structure tubulaire et une chaussette en tissu lycra en s&rsquo;inspirant de la conception des tubes de t\u00e9lescopes Dobson. Celui-ci est l\u00e9ger, d\u00e9montable et ajustable \u00e0 diff\u00e9rents rayons de courbure de miroirs.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La banc est ensuite \u00e9quip\u00e9 d&rsquo;une table crois\u00e9e xyz motoris\u00e9e permettant d&rsquo;accueillir diff\u00e9rents instruments de contr\u00f4le (Foucault, Bath, contraste de phase, \u2026). Ce dispositif permet d&rsquo;effectuer des mouvements de r\u00e9glages fins et de limiter les vibrations et turbulences dues aux op\u00e9rateurs qu&rsquo;il est possible d&rsquo;\u00e9loigner gr\u00e2ce \u00e0 un pupitre de commande.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Construction d&rsquo;un nouvel interf\u00e9rom\u00e8tre de Bath<\/span><\/strong> :<\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_5156.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6819 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_5156.jpg\" alt=\"\" width=\"4000\" height=\"3000\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_5156.jpg 4000w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_5156-300x225.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_5156-768x576.jpg 768w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/IMG_5156-1600x1200.jpg 1600w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Cet appareil sera \u00e9quip\u00e9 d&rsquo;un module laser rouge de qualit\u00e9 achet\u00e9 chez Picotronic&nbsp;: Lentille en verre focusable, longueur d&rsquo;onde calibr\u00e9e avec pr\u00e9cision (635 nm). Le choix s&rsquo;est port\u00e9 vers un laser rouge car il permet de r\u00e9gler son niveau d&rsquo;\u00e9clairement en dessous de son niveau de lasing ce qui n&rsquo;est pas possible avec un laser vert.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les composants optiques ont \u00e9t\u00e9 r\u00e9cup\u00e9r\u00e9s sur le pr\u00e9c\u00e9dent montage. Leurs supports ont toutefois \u00e9t\u00e9 am\u00e9lior\u00e9s afin de disposer de plus de possibilit\u00e9s et de finesse dans les r\u00e9glages. <\/span><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L&rsquo;appareil imageur sera quant \u00e0 lui embarqu\u00e9 sur la plate-forme xyz et disposera de r\u00e9glages fins afin d&rsquo;optimiser les alignements optiques.<\/span><\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Utilisation de la derni\u00e8re version d&rsquo;OpenFringe et de ses diff\u00e9rentes fonctionnalit\u00e9s permettant de fiabiliser les mesures&nbsp;:<\/span><\/li>\n<\/ul>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Les interf\u00e9rogrammes seront trait\u00e9s par transform\u00e9e de Fourrier (FFT), m\u00e9thode bien plus pr\u00e9cise que celle du tra\u00e7age spatial des franges. Plusieurs fronts d&rsquo;ondes seront moyenn\u00e9s pour une orientation donn\u00e9e du miroir. Chaque moyenne ainsi obtenue subira une \u00ab&nbsp;d\u00e9rotation&nbsp;\u00bb logicielle compensant la rotation physique du miroir. Une moyenne&nbsp; de ces diff\u00e9rentes orientations sera enfin r\u00e9alis\u00e9e et tendra ainsi \u00e0 annuler un \u00e9ventuel astigmatisme de pliure d\u00fb au supportage du miroir lors des contr\u00f4les.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Une nouvelle campagne de mesures est alors engag\u00e9e sur ces bases. L&rsquo;annonce des r\u00e9sultats entra\u00eene des soupirs de soulagement au sein du groupe&nbsp;:<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6820 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/400GAP_3D.jpg\" alt=\"\" width=\"772\" height=\"605\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/400GAP_3D.jpg 772w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/400GAP_3D-300x235.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/400GAP_3D-768x602.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La mod\u00e9lisation 3D du front d&rsquo;onde ne fait appara\u00eetre aucun astigmatisme&nbsp;!<\/span><br \/>\n<span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La valeur RMS ressort \u00e0 l \/ 25 sur l&rsquo;onde soit un rapport de Strelh de 94%<\/span><br \/>\n<span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La figure fait nettement appara\u00eetre le l\u00e9ger mamelonnage en forme de couronne au centre et qui avait d\u00e9j\u00e0 \u00e9t\u00e9 d\u00e9tect\u00e9 au Foucault.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">La physionomie g\u00e9n\u00e9rale du profil de l&rsquo;onde selon la m\u00e9ridienne 1 est relativement similaire \u00e0 celle issue du test de Foucault&nbsp;:<\/span><\/p>\n<p><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/400GAP_Profil.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6821 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/400GAP_Profil.jpg\" alt=\"\" width=\"1748\" height=\"744\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/400GAP_Profil.jpg 1748w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/400GAP_Profil-300x128.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/400GAP_Profil-768x327.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L&rsquo;amplitude PTV est malgr\u00e9 tout plus marqu\u00e9e ce qui est un constat r\u00e9guli\u00e8rement dress\u00e9 lorsque l&rsquo;on compare des r\u00e9sultats effectu\u00e9s \u00e0 l&rsquo;appareil de Foucault comportant un nombre limit\u00e9 de zones et ceux issus d&rsquo;un interf\u00e9rom\u00e8tre \u00e9chantillonnant une grande quantit\u00e9 de points de mesure \u00e0 la surface du miroir.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">L&rsquo;arriv\u00e9e du nouveau logiciel DFTFringe de Dale Eason nous a donn\u00e9 l&rsquo;occasion d&rsquo;affiner nos r\u00e9sultats. On constate que la vue 3D du front d&rsquo;onde initial pr\u00e9sente une surface bossel\u00e9e. Le logiciel dispose d&rsquo;un filtre Gaussien passe-bas permettant de l&rsquo;att\u00e9nuer. Avant de proc\u00e9der \u00e0 ce traitement, encore faut-il se poser la question de savoir si ces d\u00e9fauts de faibles amplitude et surface refl\u00e8tent la r\u00e9alit\u00e9 de la forme de la surface optique ou s&rsquo;ils r\u00e9sultent d&rsquo;un ph\u00e9nom\u00e8ne artificiel li\u00e9 \u00e0 l&rsquo;algorithme de reconstruction du front d&rsquo;onde. Pour aider \u00e0 trancher cette question, Dale Eason propose une m\u00e9thode&nbsp;:<\/span><\/p>\n<table style=\"width: 697px;\">\n<tbody>\n<tr>\n<td style=\"width: 219px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6823 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_1.jpg\" alt=\"\" width=\"518\" height=\"519\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_1.jpg 518w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_1-150x150.jpg 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_1-300x300.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_1-100x100.jpg 100w\" sizes=\"auto, (max-width: 518px) 100vw, 518px\" \/><\/td>\n<td style=\"width: 222.683px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6824 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_reel.jpg\" alt=\"\" width=\"228\" height=\"228\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_reel.jpg 228w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_reel-150x150.jpg 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_reel-100x100.jpg 100w\" sizes=\"auto, (max-width: 228px) 100vw, 228px\" \/><\/td>\n<td style=\"width: 217.317px;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6825 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_2.jpg\" alt=\"\" width=\"515\" height=\"519\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_2.jpg 515w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_2-150x150.jpg 150w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_2-298x300.jpg 298w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/Foucault_DFTF_2-100x100.jpg 100w\" sizes=\"auto, (max-width: 515px) 100vw, 515px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<table style=\"width: 696px;\">\n<tbody>\n<tr>\n<td style=\"width: 338.983px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/09\/3D_DFTF_1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-7834 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/09\/3D_DFTF_1.jpg\" alt=\"\" width=\"1331\" height=\"871\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/09\/3D_DFTF_1.jpg 1331w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/09\/3D_DFTF_1-300x196.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/09\/3D_DFTF_1-768x503.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<td style=\"width: 340.017px;\"><a href=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/3D_DFTF_2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-6827 size-full\" src=\"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/3D_DFTF_2.jpg\" alt=\"\" width=\"1330\" height=\"872\" srcset=\"https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/3D_DFTF_2.jpg 1330w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/3D_DFTF_2-300x197.jpg 300w, https:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/3D_DFTF_2-768x504.jpg 768w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Il pr\u00e9conise d&rsquo;utiliser la mod\u00e9lisation virtuelle d&rsquo;un Foucaulgramme \u00e0 l&rsquo;aide du logiciel et de la comparer \u00e0 un Foucaulgramme r\u00e9el du miroir puis de jouer sur le r\u00e9glage du filtre Gaussien jusqu&rsquo;\u00e0 obtenir un aspect comparable. Dans le cas pr\u00e9sent, le foucaulgramme virtuel de d\u00e9part (vue de gauche) pr\u00e9sente un mamelonnage qu&rsquo;on ne retrouve pas dans le foucaulgramme r\u00e9el (vue du centre). En proc\u00e9dant par it\u00e9rations sur la valeur de&nbsp; largeur du filtre Gaussien, nous avons obtenu un nouveau foucaultgramme (vue de droite) dont la douceur de la forme est plus fid\u00e8le \u00e0 la r\u00e9alit\u00e9. La vue 3D du front d&rsquo;onde s&rsquo;en trouve \u00e9galement liss\u00e9e. Dans ces conditions, les r\u00e9sultats de la pr\u00e9cision du miroir s&rsquo;am\u00e9liorent un peu&nbsp;: RMS = <strong>l<\/strong><strong> \/ 31<\/strong> sur l&rsquo;onde soit un rapport de Strelh de <strong>96%.<\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Bilan des contr\u00f4les&nbsp;:<\/span><\/strong><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Il aura fallu beaucoup de temps et d\u2019\u00e9nergie pour fiabiliser les mesures du miroir.<\/span><\/p>\n<p><span style=\"font-family: times\\ new\\ roman, times, serif; font-size: 20px;\">Mais cette aventure n&rsquo;aura pas \u00e9t\u00e9 vaine : Elle nous aura fait prendre conscience de la rigueur extr\u00eame qu&rsquo;il convient d&rsquo;associer aux contr\u00f4les optiques et ce d&rsquo;autant plus que les miroirs sont grands et les rapports d&rsquo;ouverture faibles. Elle nous aura enfin convaincu, s&rsquo;il en \u00e9tait besoin, qu&rsquo;une m\u00e9thode de contr\u00f4le ne peut pr\u00e9tendre seule \u00e0 \u00e9valuer la qualit\u00e9 optique d&rsquo;un miroir. Pour parvenir \u00e0 cet ambitieux objectif, seul le croisement de plusieurs m\u00e9thodes de contr\u00f4le constitue la voie \u00e0 suivre.<\/span><\/p>\n<hr>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>La r\u00e9alisation de l&rsquo;optique sera divis\u00e9e en plusieurs parties : Vous pouvez aller directement \u00e0 la section qui vous int\u00e9resse en cliquant sur l&rsquo;un des choix ci-dessous. Vous pourrez ensuite revenir directement ici avec la fl\u00e8che retour de votre navigateur. 1 &#8211; Pr\u00e9paratifs 2 &#8211; R\u00e9unissage 3 &#8211; Doucissage 4 &#8211; Polissage 5 &#8211; Parabolisation &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/gap47.astrosurf.com\/index.php\/technique\/optique-instruments\/construction-du-dobson-t-400\/realisation-miroir-400\/\" class=\"more-link\">Continuer la lecture<span class=\"screen-reader-text\"> de &laquo;&nbsp;R\u00e9alisation de l&rsquo;optique&nbsp;&raquo;<\/span><\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"parent":198,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"ngg_post_thumbnail":0,"footnotes":""},"class_list":["post-4557","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v24.8.1 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>R\u00e9alisation de l&#039;optique - L&#039;observatoire est ouvert aux visiteurs tous les vendredis soirs \u00e0 21 heures, jusqu&#039;au 3 juillet 2026 inclus, sans r\u00e9servation.<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/gap47.astrosurf.com\/index.php\/technique\/optique-instruments\/construction-du-dobson-t-400\/realisation-miroir-400\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"R\u00e9alisation de l&#039;optique - L&#039;observatoire est ouvert aux visiteurs tous les vendredis soirs \u00e0 21 heures, jusqu&#039;au 3 juillet 2026 inclus, sans r\u00e9servation.\" \/>\n<meta property=\"og:description\" content=\"La r\u00e9alisation de l&rsquo;optique sera divis\u00e9e en plusieurs parties : Vous pouvez aller directement \u00e0 la section qui vous int\u00e9resse en cliquant sur l&rsquo;un des choix ci-dessous. 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L&#039;observatoire est ouvert aux visiteurs tous les vendredis soirs \u00e0 21 heures, jusqu&#039;au 3 juillet 2026 inclus, sans r\u00e9servation.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/gap47.astrosurf.com\/index.php\/technique\/optique-instruments\/construction-du-dobson-t-400\/realisation-miroir-400\/","og_locale":"fr_FR","og_type":"article","og_title":"R\u00e9alisation de l'optique - L&#039;observatoire est ouvert aux visiteurs tous les vendredis soirs \u00e0 21 heures, jusqu&#039;au 3 juillet 2026 inclus, sans r\u00e9servation.","og_description":"La r\u00e9alisation de l&rsquo;optique sera divis\u00e9e en plusieurs parties : Vous pouvez aller directement \u00e0 la section qui vous int\u00e9resse en cliquant sur l&rsquo;un des choix ci-dessous. Vous pourrez ensuite revenir directement ici avec la fl\u00e8che retour de votre navigateur. 1 &#8211; Pr\u00e9paratifs 2 &#8211; R\u00e9unissage 3 &#8211; Doucissage 4 &#8211; Polissage 5 &#8211; Parabolisation &hellip; Continuer la lecture de &laquo;&nbsp;R\u00e9alisation de l&rsquo;optique&nbsp;&raquo;","og_url":"https:\/\/gap47.astrosurf.com\/index.php\/technique\/optique-instruments\/construction-du-dobson-t-400\/realisation-miroir-400\/","og_site_name":"L&#039;observatoire est ouvert aux visiteurs tous les vendredis soirs \u00e0 21 heures, jusqu&#039;au 3 juillet 2026 inclus, sans r\u00e9servation.","article_publisher":"https:\/\/www.facebook.com\/astrogap47\/","article_modified_time":"2019-12-19T16:50:23+00:00","og_image":[{"url":"http:\/\/gap47.astrosurf.com\/wp-content\/uploads\/2018\/05\/DSCF1247.jpg","type":"","width":"","height":""}],"twitter_card":"summary_large_image","twitter_misc":{"Dur\u00e9e de lecture estim\u00e9e":"38 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/gap47.astrosurf.com\/index.php\/technique\/optique-instruments\/construction-du-dobson-t-400\/realisation-miroir-400\/","url":"https:\/\/gap47.astrosurf.com\/index.php\/technique\/optique-instruments\/construction-du-dobson-t-400\/realisation-miroir-400\/","name":"R\u00e9alisation de l'optique - 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